GATE Exam 2018 Computer Science and Information Technology (CS) Question Paper With Answer Key

Computer Science and Information Technology

General Aptitude (GA) Set-3

Q. 1 – Q. 5 carry one mark each.

1. “ From where are they bringing their books? ________ bringing _______ books from _____.”

The words that best fill the blanks in the above sentence are

(A) Their, they’re, there

(B) They’re, their, there

(C) There, their, they’re

(D) They’re, there, there

Answer: (B)

2. “ A _________ investigation can sometimes yield new facts, but typically organized ones are more successful.”

The word that best fills the blank in the above sentence is

(A) meandering

(B) timely

(C) consistent

(D) systematic

Answer: (A)

3. The area of a square is 𝑑. What is the area of the circle which has the diagonal of the square as its diameter?

(A) 𝜋𝑑

(B) 𝜋𝑑2

Answer: (D)

4. W hat would be the smallest natural number which when divided either by 20 or by 42 or by 76 leaves a remainder of 7 in each case?

(A) 3047

(B) 6047

(C) 7987

(D) 63847

Answer: (C)

5. What is the missing number in the following sequence?

2, 12, 60, 240, 720, 1440, _____, 0

(A) 2880

(B) 1440

(C) 720

(D) 0

Answer: (B)

Q. 6 – Q. 10 carry two marks each.

6. In appreciation of the social improvements completed in a town, a wealthy philanthropist decided to gift Rs 750 to each male senior citizen in the town and Rs 1000 to each female senior citizen. Altogether, there were 300 senior citizens eligible for this gift. However, only 8/9th of the eligible men and 2/3rd of the eligible women claimed the gift. How much money (in Rupees) did the philanthropist give away in total?

(A) 1,50,000

(B) 2,00,000

(C) 1,75,000

(D) 1,51,000

Answer: (B)

7. If 𝑝𝑞𝑟 ≠ 0 and what is the value of the product 𝑥𝑦𝑧?

(A) −1

(B) 1/pqr

(C) 1

(D) 𝑝𝑞𝑟

Answer: (C)

8. In a party, 60% of the invited guests are male and 40% are female. If 80% of the invited  guests attended the party and if all the invited female guests attended, what would be the ratio of males to females among the attendees in the party?

(A) 2:3

(B) 1:1

(C) 3:2

(D) 2:1

Answer: (B)

9. In the figure below, ∠𝐷𝐸𝐶 + ∠𝐵𝐹𝐶 is equal to ____________

(A) ∠𝐵𝐶𝐷 − ∠𝐵𝐴𝐷

(B) ∠𝐵𝐴𝐷 + ∠𝐵𝐶𝐹

(C) ∠𝐵𝐴𝐷 + ∠𝐵𝐶𝐷

(D) ∠𝐶𝐵𝐴 + ∠𝐴𝐷𝐶

Answer: (A)

10. A six sided unbiased die with four green faces and two red faces is rolled seven times. Which of the following combinations is the most likely outcome of the experiment?

(A) Three green faces and four red faces.

(B) Four green faces and three red faces.

(C) Five green faces and two red faces.

(D) Six green faces and one red face.

Answer: (C)

COMPUTER SCIENCE AND INFORMATION TECHNOLOGY

Q. 1 – Q. 25 carry one mark each.

1. Which one of the following is a closed form expression for the generating function of the
sequence {an}, where an = 2n + 3 for all n = 0, 1, 2,… ?

Answer: (D)

2. Consider the following C program.

The output of this program is:

(A) 0, c

(B) 0, a+2

(C) ‘0’, ‘a+2’

(D) ‘0’, ‘c’

Answer: (A)

3. A queue is implemented using a non-circular singly linked list. The queue has a head pointer and a tail pointer, as shown in the figure. Let n denote the number of nodes in the queue. Let enqueue be implemented by inserting a new node at the head, and dequeue be implemented by deletion of a node from the tail.

Which one of the following is the time complexity of the most time-efficient implementation of enqueue and dequeue, respectively, for this data structure?

(A) θ(1), θ(1)

(B) θ(1), θ(n)

(C) θ(n), θ(1)

(D) θ(n), θ(n)

Answer: (B)

4. Let ⊕ and ⊙ denote the Exclusive OR and Exclusive NOR operations, respectively. Which one of the following is NOT CORRECT?

Answer: (D)

5. Consider the following processor design characteristics.

I. Register-to-register arithmetic operations only

II. Fixed-length instruction format

III. Hardwired control unit

Which of the characteristics above are used in the design of a RISC processor?

(A) I and II only

(B) II and III only

(C) I and III only

(D) I, II and III

Answer: (D)

6. Let N be an NFA with n states. Let k be the number of states of a minimal DFA which is equivalent to N. Which one of the following is necessarily true?

(A) 𝑘 ≥ 2𝑛

(B) 𝑘 ≥ 𝑛

(C) 𝑘 ≤ 𝑛2

(D) 𝑘 ≤ 2𝑛

Answer: (D)

7. The set of all recursively enumerable languages is

(A) closed under complementation.

(B) closed under intersection.

(C) a subset of the set of all recursive languages.

(D) an uncountable set.

Answer: (B)

8. Which one of the following statements is FALSE?

(A) Context-free grammar can be used to specify both lexical and syntax rules.

(B) Type checking is done before parsing.

(C) High-level language programs can be translated to different Intermediate Representations.

(D) Arguments to a function can be passed using the program stack.

Answer: (B)

9. The following are some events that occur after a device controller issues an interrupt while process L is under execution.

(P) The processor pushes the process status of L onto the control stack.

(Q) The processor finishes the execution of the current instruction.

(R) The processor executes the interrupt service routine.

(S) The processor pops the process status of L from the control stack.

(T) The processor loads the new PC value based on the interrupt.

Which one of the following is the correct order in which the events above occur?

(A) QPTRS

(B) PTRSQ

(C) TRPQS

(D) QTPRS

Answer: (A)

10. Consider a process executing on an operating system that uses demand paging. The average time for a memory access in the system is M units if the corresponding memory page is available in memory, and D units if the memory access causes a page fault. It has been experimentally measured that the average time taken for a memory access in the process is X units.

Which one of the following is the correct expression for the page fault rate experienced by the process?

(A) (D – M) / (X – M)

(B) (X – M) / (D – M)

(C) (D – X) / (D – M)

(D) (X – M) / (D – X)

Answer: (B)

11. In an Entity-Relationship (ER) model, suppose R is a many-to-one relationship from entity set E1 to entity set E2. Assume that E1 and E2 participate totally in R and that the cardinality of E1 is greater than the cardinality of E2.

Which one of the following is true about 𝑅?

(A) Every entity in E1 is associated with exactly one entity in E2.

(B) Some entity in E1 is associated with more than one entity in E2.

(C) Every entity in E2 is associated with exactly one entity in E1.

(D) Every entity in E2 is associated with at most one entity in E1.

Answer: (A)

12. Consider the following two tables and four queries in SQL.

Which one of the queries above is certain to have an output that is a superset of the outputs of the other three queries?

(A) Query 1

(B) Query 2

(C) Query 3

(D) Query 4

Answer: (D)

13. Match the following:

(A) P-III, Q-IV, R-II, S-I

(B) P-II, Q-I, R-IV, S-III

(C) P-IV, Q-I, R-II, S-III

(D) P-IV, Q-I, R-III, S-II

Answer: (C)

14. Consider the following statements regarding the slow start phase of the TCP congestion control algorithm. Note that cwnd stands for the TCP congestion window and MSS denotes the Maximum Segment Size.

(i) The cwnd increases by 2 MSS on every successful acknowledgment.

(ii) The cwnd approximately doubles on every successful acknowledgement.

(iii) The cwnd increases by 1 MSS every round trip time.

(iv) The cwnd approximately doubles every round trip time.

Which one of the following is correct?

(A) Only (ii) and (iii) are true

(B) Only (i) and (iii) are true

(C) Only (iv) is true

(D) Only (i) and (iv) are true

Answer: (C)

15. Two people, P and Q, decide to independently roll two identical dice, each with 6 faces, numbered 1 to 6. The person with the lower number wins. In case of a tie, they roll the dice repeatedly until there is no tie. Define a trial as a throw of the dice by P and Q. Assume that all 6 numbers on each dice are equi-probable and that all trials are independent. The probability (rounded to 3 decimal places) that one of them wins on the third trial is _____.

Answer: (0.021 to 0.024)

16. The value of correct to three decimal places
(assuming that 𝜋 = 3.14 ) is _____.

Answer: (0.27 to 0.30)

17. Consider a matrix Note that vT denotes the transpose of v. The largest eigenvalue of A is _____.

Answer: (3 to 3)

18. The chromatic number of the following graph is _______.

Answer: (3 to 3)

19. Let G be a finite group on 84 elements. The size of a largest possible proper subgroup of G is ________.

Answer: (42 to 42)

20. The postorder traversal of a binary tree is 8,9,6,7,4,5,2,3,1. The inorder traversal of the same tree is 8,6,9,4,7,2,5,1,3. The height of a tree is the length of the longest path from the root to any leaf. The height of the binary tree above is ______.

Answer: (4 to 4)

21. Consider the following C program:

The output of this program is _____.

Answer: (4 to 4)

22. Consider the sequential circuit shown in the figure, where both flip-flops used are positive edge-triggered D flip-flops.

The number of states in the state transition diagram of this circuit that have a transition back to the same state on some value of “in” is _____. 

Answer: (2 to 2)

23. A 32-bit wide main memory unit with a capacity of 1 GB is built using 256M × 4-bit DRAM chips. The number of rows of memory cells in the DRAM chip is 214. The time taken to perform one refresh operation is 50 nanoseconds. The refresh period is 2 milliseconds. The percentage (rounded to the closest integer) of the time available for performing the memory read/write operations in the main memory unit is __________.

Answer: (59.0 to 60.0)

24. Consider a system with 3 processes that share 4 instances of the same resource type. Each process can request a maximum of 𝐾 instances. Resource instances can be requested and released only one at a time. The largest value of 𝐾 that will always avoid deadlock is ____.

Answer: (2 to 2)

25. Consider a long-lived TCP session with an end-to-end bandwidth of 1 Gbps (= 109 bits-persecond). The session starts with a sequence number of 1234. The minimum time (in seconds, rounded to the closest integer) before this sequence number can be used again is _______.

Answer: (34 to 35)

Q. 26 – Q. 55 carry two marks each.

26. Consider a matrix P whose only eigenvectors are the multiples of 

Consider the following statements.

(I) P does not have an inverse

(II) P has a repeated eigenvalue

(III) P cannot be diagonalized

Which one of the following options is correct?

(A) Only I and III are necessarily true

(B) Only II is necessarily true

(C) Only I and II are necessarily true

(D) Only II and III are necessarily true

Answer: (D)

27. Let N be the set of natural numbers. Consider the following sets.

P: Set of Rational numbers (positive and negative)

Q: Set of functions from {0, 1} to N

R: Set of functions from N to {0, 1}

S: Set of finite subsets of N.

Which of the sets above are countable?

(A) Q and S only

(B) P and S only

(C) P and R only

(D) P, Q and S only

Answer: (D)

28. Consider the first-order logic sentence

where 𝜓(𝑠, 𝑡, 𝑢, 𝑣, 𝑤, 𝑥, 𝑦) is a quantifier-free first-order logic formula using only predicate symbols, and possibly equality, but no function symbols. Suppose 𝜑 has a model with a universe containing 7 elements.

Which one of the following statements is necessarily true?

(A) There exists at least one model of 𝜑 with universe of size less than or equal to 3.

(B) There exists no model of 𝜑 with universe of size less than or equal to 3.

(C) There exists no model of 𝜑 with universe of size greater than 7.

(D) Every model of 𝜑 has a universe of size equal to 7.

Answer: (A)

29. Consider the following C program:

The output of the program above is

(A) Hi Bye Bye Hi

(B) Hi Bye Hi Bye

(C) Bye Hi Hi Bye

(D) Bye Hi Bye Hi

Answer: (A)

30. Let G be a simple undirected graph. Let TD be a depth first search tree of G. Let TB be a breadth first search tree of G. Consider the following statements. 

(I) No edge of G is a cross edge with respect to TD. (A cross edge in G is between two nodes neither of which is an ancestor of the other in TD.)

(II) For every edge (u,v) of G, if u is at depth i and v is at depth j in TB, then |𝑖 − 𝑗| = 1. Which of the statements above must necessarily be true?

(A) I only

(B) II only

(C) Both I and II

(D) Neither I nor II

Answer: (A)

31. Assume that multiplying a matrix G1 of dimension 𝑝 × 𝑞 with another matrix G2 of dimension 𝑞 × 𝑟 requires 𝑝𝑞𝑟 scalar multiplications. Computing the product of n matrices G1G2G3…Gn can be done by parenthesizing in different ways. Define Gi Gi+1 as an explicitly computed pair for a given paranthesization if they are directly multiplied. For example, in the matrix multiplication chain G1G2G3G4G5G6 using parenthesization (G1(G2G3))(G4(G5G6)), G2G3 and G5G6 are the only explicitly computed pairs. 

Consider a matrix multiplication chain F1F2F3F4F5, where matrices F1, F2, F3, F4 and F5 are of dimensions 2×25, 25×3, 3×16, 16×1 and 1×1000, respectively. In the parenthesization of F1F2F3F4F5 that minimizes the total number of scalar multiplications, the explicitly computed pairs is/are

(A) F1F2 and F3F4 only

(B) F2F3 only

(C) F3F4 only

(D) F1F2 and F4F5 only

Answer: (C)

32. Consider the following C code. Assume that unsigned long int type length is 64 bits.

The value returned when we call fun with the input 240 is

(A) 4

(B) 5

(C) 6

(D) 40

Answer: (B)

33. Consider the unsigned 8-bit fixed point binary number representation below,

b7 b6 b5 b4 b3 . b2 b1 b0

where the position of the binary point is between b3 and b2. Assume b7 is the most significant bit. Some of the decimal numbers listed below cannot be represented exactly in the above representation:

(i) 31.500 (ii) 0.875 (iii) 12.100 (iv) 3.001

Which one of the following statements is true?

(A) None of (i), (ii), (iii), (iv) can be exactly represented

(B) Only (ii) cannot be exactly represented

(C) Only (iii) and (iv) cannot be exactly represented

(D) Only (i) and (ii) cannot be exactly represented

Answer: (C)

34. The size of the physical address space of a processor is 2𝑃 bytes. The word length is 2𝑊 bytes. The capacity of cache memory is 2𝑁 bytes. The size of each cache block is 2𝑀 words. For a 𝐾-way set-associative cache memory, the length (in number of bits) of the tag field is

(A) 𝑃 − 𝑁 − log2 𝐾

(B) 𝑃 − 𝑁 + log2 𝐾

(C) 𝑃 − 𝑁 − 𝑀 − 𝑊 − log2 𝐾

(D) 𝑃 − 𝑁 − 𝑀 − 𝑊 + log2 𝐾

Answer: (B)

35. Consider the following languages:

Which of the languages above are context-free?

(A) I and IV only

(B) I and II only

(C) II and III only

(D) II and IV only

Answer: (B)

36. Consider the following problems. 𝐿(𝐺) denotes the language generated by a grammar 𝐺. 𝐿(𝑀) denotes the language accepted by a machine 𝑀.

(I) For an unrestricted grammar 𝐺 and a string 𝑤, whether 𝑤 ∈ 𝐿(𝐺)

(II) Given a Turing machine M, whether L(M) is regular

(III) Given two grammars 𝐺1 and 𝐺2, whether 𝐿(𝐺1) = 𝐿(𝐺2)

(IV) Given an NFA N, whether there is a deterministic PDA P such that N and P accept the same language.

Which one of the following statements is correct?

(A) Only I and II are undecidable

(B) Only III is undecidable

(C) Only II and IV are undecidable

(D) Only I, II and III are undecidable

Answer: (D)

37. A lexical analyzer uses the following patterns to recognize three tokens T1, T2, and T3 over the alphabet {a,b,c}.

Note that ‘x?’ means 0 or 1 occurrence of the symbol x. Note also that the analyzer outputs the token that matches the longest possible prefix.

If the string 𝑏𝑏𝑎𝑎𝑐𝑎𝑏𝑐 is processed by the analyzer, which one of the following is the sequence of tokens it outputs?

(A) 𝑇1𝑇2𝑇3

(B) 𝑇1𝑇1𝑇3

(C) 𝑇2𝑇1𝑇3

(D) 𝑇3𝑇3

Answer: (D)

38. Consider the following parse tree for the expression a#b$c$d#e#f, involving two binary operators $ and #.

Which one of the following is correct for the given parse tree?

(A) $ has higher precedence and is left associative; # is right associative

(B) # has higher precedence and is left associative; $ is right associative

(C) $ has higher precedence and is left associative; # is left associative

(D) # has higher precedence and is right associative; $ is left associative

Answer: (A)

39. I0n a system, there are three types of resources: E, F and G. Four processes P0, P1, P2 and P3 execute concurrently. At the outset, the processes have declared their maximum resource requirements using a matrix named Max as given below. For example, Max[P2,F] is the maximum number of instances of F that P2 would require. The number of instances of the resources allocated to the various processes at any given state is given by a matrix named Allocation.

Consider a state of the system with the Allocation matrix as shown below, and in which 3 instances of E and 3 instances of F are the only resources available.

From the perspective of deadlock avoidance, which one of the following is true? 

(A) The system is in safe state. 

(B) The system is not in safe state, but would be safe if one more instance of E were available

(C) The system is not in safe state, but would be safe if one more instance of F were available

(D) The system is not in safe state, but would be safe if one more instance of G were available

Answer: (A)

40. C onsider the following solution to the producer-consumer synchronization problem. The shared buffer size is 𝑁. Three semaphores empty, full and mutex are defined with respective initial values of 0, 𝑁 and 1. Semaphore empty denotes the number of available slots in the buffer, for the consumer to read from. Semaphore full denotes the number of available slots 
in the buffer, for the producer to write to. The placeholder variables, denoted by P, Q, R, and S, in the code below can be assigned either empty or full. The valid semaphore operations are: wait() and signal().

Which one of the following assignments to P, Q, R and S will yield the correct solution?

(A) P: full, Q: full, R: empty, S: empty

(B) P: empty, Q: empty, R: full, S: full

(C) P: full, Q: empty, R: empty, S: full

(D) P: empty, Q: full, R: full, S: empty

Answer: (C)

41. C onsider the relations r(A, B) and s(B, C), where s.B is a primary key and r.B is a foreign key referencing s.B. Consider the query

Let LOJ denote the natural left outer-join operation. Assume that r and s contain no null values.

Which one of the following queries is NOT equivalent to Q?

(A) 𝜎𝐵<5(𝑟 ⋈ 𝑠)

(B) 𝜎𝐵<5(𝑟 𝐿𝑂𝐽 𝑠)

(C) 𝑟 𝐿𝑂𝐽 (𝜎𝐵<5(𝑠))

(D) 𝜎𝐵<5(𝑟) 𝐿𝑂𝐽 𝑠

Answer: (C)

42. Consider the following four relational schemas. For each schema, all non-trivial functional dependencies are listed. The underlined attributes are the respective primary keys.

Which one of the relational schemas above is in 3NF but not in BCNF?

(A) Schema I

(B) Schema II

(C) Schema III

(D) Schema IV

Answer: (B)

43. Let G be a graph with 100! vertices, with each vertex labelled by a distinct permutation of the numbers 1,2, … , 100. There is an edge between vertices 𝑢 and 𝑣 if and only if the label of 𝑢 can be obtained by swapping two adjacent numbers in the label of 𝑣. Let 𝑦 denote the degree of a vertex in G, and 𝑧 denote the number of connected components in G. Then, 𝑦 + 10𝑧 = _____.

Answer: (109 to 109)

44. Consider Guwahati (G) and Delhi (D) whose temperatures can be classified as high (𝐻), medium (𝑀) and low (𝐿). Let 𝑃(𝐻𝐺 ) denote the probability that Guwahati has high temperature. Similarly, 𝑃(𝑀𝐺 ) and 𝑃(𝐿𝐺 ) denotes the probability of Guwahati having medium and low temperatures respectively. Similarly, we use 𝑃(𝐻𝐷 ), 𝑃(𝑀𝐷) and 𝑃(𝐿𝐷) for Delhi.

The following table gives the conditional probabilities for Delhi’s temperature given Guwahati’s temperature.

Consider the first row in the table above. The first entry denotes that if Guwahati has high temperature (𝐻𝐺 ) then the probability of Delhi also having a high temperature (𝐻𝐷) is 0.40; i.e., 𝑃(𝐻𝐷|𝐻𝐺 ) = 0.40. Similarly, the next two entries are 𝑃(𝑀𝐷|𝐻𝐺 ) = 0.48 and 𝑃(𝐿𝐷|𝐻𝐺 ) = 0.12. Similarly for the other rows.

If it is known that 𝑃(𝐻𝐺 ) = 0.2, 𝑃(𝑀𝐺 ) = 0.5, and 𝑃(𝐿𝐺 ) = 0.3, then the probability (correct to two decimal places) that Guwahati has high temperature given that Delhi has high temperature is _______.

Answer: (0.60 to 0.62)

45. Consider the following program written in pseudo-code. Assume that x and y are integers.

The number of times that the print statement is executed by the call Count(1024,1024) is _____.

Answer: (10230 to 10230)

46. The number of possible min-heaps containing each value from {1, 2, 3, 4, 5, 6, 7}exactly once is _____.

Answer: (80 to 80)

47. Consider the following undirected graph G:

Choose a value for x that will maximize the number of minimum weight spanning trees (MWSTs) of G. The number of MWSTs of G for this value of x is ______.

Answer: (4 to 4)

48. Consider the weights and values of items listed below. Note that there is only one unit of each item.

The task is to pick a subset of these items such that their total weight is no more than 11 Kgs and their total value is maximized. Moreover, no item may be split. The total value of items picked by an optimal algorithm is denoted by 𝑉opt. A greedy algorithm sorts the items by their value-to-weight ratios in descending order and packs them greedily, starting from the first item in the ordered list. The total value of items picked by the greedy algorithm is denoted by 𝑉greedy. The value of 𝑉opt − 𝑉greedy is ____________.

Answer: (16 to 16)

49. Consider the minterm list form of a Boolean function 𝐹 given below.

Here, 𝑚 denotes a minterm and 𝑑 denotes a don’t care term. The number of essential prime implicants of the function 𝐹 is ______.

50. The instruction pipeline of a RISC processor has the following stages: Instruction Fetch (IF), Instruction Decode (ID), Operand Fetch (OF), Perform Operation (PO) and Writeback (WB). The IF, ID, OF and WB stages take 1 clock cycle each for every instruction. Consider a sequence of 100 instructions. In the PO stage, 40 instructions take 3 clock cycles each, 35 instructions take 2 clock cycles each, and the remaining 25 instructions take 1 clock cycle each. Assume that there are no data hazards and no control hazards. 

The number of clock cycles required for completion of execution of the sequence of instructions is ______.

Answer: (219 to 219)

51. A processor has 16 integer registers (R0, R1, .. , R15) and 64 floating point registers (F0, F1,… , F63). It uses a 2-byte instruction format. There are four categories of instructions: Type-1, Type-2, Type-3, and Type-4. Type-1 category consists of four instructions, each with 3 integer register operands (3Rs). Type-2 category consists of eight instructions, each with 2 floating point register operands (2Fs). Type-3 category consists of fourteen instructions, each with one integer register operand and one floating point register operand (1R+1F). Type-4 category consists of N instructions, each with a floating point register
operand (1F).

The maximum value of N is __________.

Answer: (32 to 32)

52. Given a language 𝐿, define 𝐿𝑖 as follows:

The order of a language L is defined as the smallest k such that 𝐿𝑘 = 𝐿𝑘+1.

Consider the language L1 (over alphabet 0) accepted by the following automaton.

The order of L1 is _____.

Answer: (2 to 2)

53. Consider a storage disk with 4 platters (numbered as 0, 1, 2 and 3), 200 cylinders (numbered as 0, 1, … , 199), and 256 sectors per track (numbered as 0, 1, … , 255). The following 6 disk requests of the form [sector number, cylinder number, platter number] are received by the disk controller at the same time:

[120, 72, 2] , [180, 134, 1] , [60, 20, 0] , [212, 86, 3] , [56, 116, 2] , [118, 16, 1]

Currently the head is positioned at sector number 100 of cylinder 80, and is moving towards higher cylinder numbers. The average power dissipation in moving the head over 100 cylinders is 20 milliwatts and for reversing the direction of the head movement once is 15 milliwatts. Power dissipation associated with rotational latency and switching of head between different platters is negligible.

The total power consumption in milliwatts to satisfy all of the above disk requests using the Shortest Seek Time First disk scheduling algorithm is _______.

Answer: (85 to 85)

54. Consider an IP packet with a length of 4,500 bytes that includes a 20-byte IPv4 header and a 40-byte TCP header. The packet is forwarded to an IPv4 router that supports a Maximum Transmission Unit (MTU) of 600 bytes. Assume that the length of the IP header in all the outgoing fragments of this packet is 20 bytes. Assume that the fragmentation offset value stored in the first fragment is 0.

The fragmentation offset value stored in the third fragment is _______.

Answer: (144 to 144)

55. Consider a simple communication system where multiple nodes are connected by a shared broadcast medium (like Ethernet or wireless). The nodes in the system use the following carrier-sense based medium access protocol. A node that receives a packet to transmit will carrier-sense the medium for 5 units of time. If the node does not detect any other transmission in this duration, it starts transmitting its packet in the next time unit. If the node detects another transmission, it waits until this other transmission finishes, and then begins  to carrier-sense for 5 time units again. Once they start to transmit, nodes do not perform any collision detection and continue transmission even if a collision occurs. All transmissions last for 20 units of time. Assume that the transmission signal travels at the speed of 10 meters per unit time in the medium.

Assume that the system has two nodes P and Q, located at a distance d meters from each other. P starts transmitting a packet at time t=0 after successfully completing its carrier-sense phase. Node Q has a packet to transmit at time t=0 and begins to carrier-sense the medium.

The maximum distance d (in meters, rounded to the closest integer) that allows Q to successfully avoid a collision between its proposed transmission and P’s ongoing transmission is _____.

Answer: (50 to 50)

GATE Exam 2018 Chemical Engineering (CH) Question Paper With Answer Key

CHEMICAL ENGINEERING

General Aptitude (GA) Set-4

Q. 1 – Q. 5 carry one mark each.

1. “ When she fell down the _______, she received many _______ but little help.”

The words that best fill the blanks in the above sentence are

(A) stairs, stares

(B) stairs, stairs

(C) stares, stairs

(D) stares, stares

Answer: (A)

2.  “ In spite of being warned repeatedly, he failed to correct his _________ behaviour.”

The word that best fills the blank in the above sentence is

(A) rational

(B) reasonable

(C) errant

(D) good

Answer: (C)

3. For 0 ≤ 𝑥 ≤ 2𝜋, sin 𝑥 and cos 𝑥 are both decreasing functions in the interval ________.

(A) 

(B) 

(C) 

(D) 

Answer: (B)

4. The area of an equilateral triangle is √3. What is the perimeter of the triangle?

(A) 2

(B) 4

(C) 6

(D) 8

Answer: (C)

5. Arrange the following three-dimensional objects in the descending order of their volumes:

(i) A cuboid with dimensions 10 cm, 8 cm and 6 cm

(ii) A cube of side 8 cm

(iii) A cylinder with base radius 7 cm and height 7 cm

(iv) A sphere of radius 7 cm

(A) (i), (ii), (iii), (iv)

(B) (ii), (i), (iv), (iii)

(C) (iii), (ii), (i), (iv)

(D) (iv), (iii), (ii), (i)

Answer: (D)

Q. 6 – Q. 10 carry two marks each.

6. An automobile travels from city A to city B and returns to city A by the same route. The speed of the vehicle during the onward and return journeys were constant at 60 km/h and 90 km/h, respectively. What is the average speed in km/h for the entire journey?

(A) 72

(B) 73

(C) 74

(D) 75

Answer: (A)

7. A set of 4 parallel lines intersect with another set of 5 parallel lines. How many parallelograms are formed?

(A) 20

(B) 48

(C) 60

(D) 72

Answer: (C)

8. To pass a test, a candidate needs to answer at least 2 out of 3 questions correctly. A total of 6,30,000 candidates appeared for the test. Question A was correctly answered by 3,30,000 candidates. Question B was answered correctly by 2,50,000  candidates. Question C was answered correctly by 2,60,000 candidates. Both questions A and B were answered correctly by 1,00,000 candidates. Both questions B and C were answered correctly by 90,000 candidates. Both questions A and C were answered correctly by 80,000 candidates. If the number of students answering all questions correctly is the same as the number answering none, how many candidates failed to clear the test?

(A) 30,000

(B) 2,70,000

(C) 3,90,000

(D) 4,20,000

Answer: (D)

9. If 𝑥2 + 𝑥 − 1 = 0 what is the value of 

(A) 1

(B) 5

(C) 7

(D) 9

Answer: (C)

10. In a detailed study of annual crow births in India, it was found that there was relatively no growth during the period 2002 to 2004 and a sudden spike from 2004 to 2005. In another unrelated study, it was found that the revenue from cracker sales in India which remained fairly flat from 2002 to 2004, saw a sudden spike in 2005 before declining again in 2006. The solid line in the graph below refers to annual sale of crackers and the dashed line refers to the annual crow births in India. Choose the most appropriate inference from the above data.

(A) There is a strong correlation between crow birth and cracker sales.

(B) Cracker usage increases crow birth rate.

(C) If cracker sale declines, crow birth will decline.

(D) Increased birth rate of crows will cause an increase in the sale of crackers.

Answer: (A)

CHEMICAL ENGINEERING

Q. 1 – Q. 25 carry one mark each.

1. Consider the following two equations:

The above set of equations is represented by

Answer: (C)

2. The fourth order Runge-Kutta (RK4) method to solve an ordinary differential equation is given as

For a special case when the function f depends solely on x, the above RK4 method reduces to

(A) Euler’s explicit method

(B) Trapezoidal rule

(C) Euler’s implicit method

(D) Simpson’s 1/3 rule

Answer: (D)

3. A watch uses two electronic circuits (ECs). Each EC has a failure probability of 0.1 in one year of operation. Both ECs are required for functioning of the watch. The probability of the watch functioning for one year without failure is

(A) 0.99

(B) 0.90

(C) 0.81

(D) 0.80

Answer: (C)

4. The figure which represents (x in radians) is

Answer: (B)

5. The terminal velocity of a spherical particle in gravitational settling under Stokes’ regime varies

(A) linearly with the particle diameter

(B) linearly with the viscosity of the liquid

(C) directly with the square of particle diameter

(D) inversely with the density of particle

Answer: (C)

6. Critical speed of a ball mill depends on

(A) the radius of the mill (shell) and the radius of the particles

(B) the radius of the mill (shell) and the density of the particles

(C) the radius of the balls and the radius of the particles

(D) the radius of the balls and the radius of the mill (shell)

Answer: (D)

7. Economy of evaporators used for concentrating sugarcane juice is

Answer: (C)

8. Segmental baffles in a 2-4 shell and tube heat exchanger

(A) change the flow pattern of the tube side fluid and increase the overall heat transfer coefficient

(B) increase the heat transfer coefficient in the shell side and support the tubes

(C) help to reduce the thermal expansion of the tubes and increase the heat transfer coefficient in the tube side

(D) increase the number of passes in the shell side and increase the heat transfer coefficient in the tube side

Answer: (B)

9. In connection with petroleum refining, identify the incorrect statement among the following options.

(A) Desalting of crude oil is done before processing it in atmospheric distillation unit

(B) A stream of hydrogen is produced in catalytic reforming of naphtha

(C) Asphalt used for paving is a petroleum product

(D) Cetane number indicates the quality of petrol / motor spirit

Answer: (D)

10. Polyvinyl chloride is produced by

(A) co-polymerization

(B) addition-type kinetics

(C) reacting chlorine with polyethylene

(D) reacting hydrochloric acid with polyethylene

Answer: (B)

11. The molecular formula of the predominant chemical compound in commercial sugar is

(A) C12H22O11

(B) C12H24O12

(C) C6H10O5

(D) C6H12O6

Answer: (A)

12. Two packed towers are designed for the same mass velocity of the gas. The first has liquid and gas flow rates of 30 kg/s and 1.2 kg/s, respectively, while the corresponding flow rates in the second tower are 67.5 kg/s and 1.8 kg/s. The ratio of the design diameter of the wider tower to that of the narrower tower is

(A) 2

(B) 1.8

(C) 1.5

(D) 1.225

Answer: (D)

13. The Annual Fixed Charges (AFC) and Annual Utilities Costs (AUC) of a distillation column being designed are expressed in terms of the reflux ratio (R) as

The reflux ratio (Ropt) for optimizing the total cost of the distillation column may be found by solving

Answer: (B)

14. Consider the following properties:

(P) temperature

(Q) specific gravity

(R) chemical potential

(S) volume

The option which lists ALL the intensive properties is

(A) P

(B) P and Q

(C) P, Q and R

(D) P, Q, R and S

Answer: (C)

15. Liquid phase isomerization of o-xylene to p-xylene using a zeolite catalyst was carried out in a CSTR. Three sets of kinetic data at different temperatures and stirring speeds were obtained as shown below.

The operating condition at which the reaction rate is not controlled by external mass transfer resistance is

(A) T = 500 K; rpm = 3000

(B) T = 600 K; rpm = 1000

(C) T = 700 K; rpm = 1000

(D) T = 700 K; rpm = 2000

Answer: (A)

16. Choose the correct statement

In viscose rayon manufacturing process,

(A) carbon disulphide used as reactant for xanthate formation is regenerated in a later step

(B) caustic soda used as reactant for steeping of cellulose is regenerated in a later step

(C) sulphuric acid is used in steeping process of cellulose

(D) the spun viscose rayon is hardened in an alkali bath

Answer: (A)

17. The reactant (M) is converted into product (N) in the presence of catalyst in a fixed bed reactor. All the flow rates (F, G, H, P and R) in mol/s, and mole fraction of reactant (M) in these streams (xF, xG, xH, xP and xR) are shown in the diagram.

The overall fractional conversion is

Answer: (D)

18. A first-order process having a transfer function, is controlled by a proportional controller with gain of 3.2. The process time constant is in minutes. Addition of the integral control action with an integral time constant of 5 minutes leads to increase in

(A) offset

(B) speed of response

(C) order of the closed loop system

(D) proportional band

Answer: (C)

19. According to the surface renewal theory, the unit of fractional rate of surface renewal is

(A) m2 s-2

(B) m2 s-1

(C) m s-1

(D) s-1

Answer: (D)

20. For absorption of H2S from a mixture with hydrocarbon vapour into an aqueous alkanolamine solution, the liquid phase mass transfer resistance is

(A) significantly higher than that of the gas phase

(B) negligible compared to that of the gas phase

(C) equal to that of the gas phase

(D) dependent on the gas phase mass transfer resistance

Answer: (B)

21. For a chemical reaction, the ratio of rate constant at 500 K to that at 400 K is 2.5. Given R = 8.314 J mol-1 K-1, the value of activation energy (in kJ/mol) is

(A) 10.5

(B) 12.0

(C) 15.2

(D) 18.4

Answer: (C)

22. Pitot tube is used to measure

(A) liquid level in a tank

(B) flow velocity at a point

(C) angular deformation

(D) vorticity

Answer: (B)

23. A venturi meter is installed to measure the flow rate of water in a 178 mm diameter (ID) pipe. The throat diameter is 102 mm. The differential pressure measured using a manometer is 154.3 kN/m2. The data given are:
discharge coefficient = 0.98; water density = 1000 kg/m3. The volumetric flow rate of water (in m3/s) is _________.

Answer: (0.145 to 0.155)

24. The ammonia (NH3) oxidation process occurs over a catalyst as

4NH3 + 5O2 → 6H2O + 4NO

Air is supplied such that oxygen (O2) is 20% in excess of that required for complete conversion of NH3. The mole fraction of O2 in inlet gas mixture (NH3 + air) is ______ (rounded off to third decimal place)

Answer: (0.170 to 0.200)

25. The initial water level in a tank is 4 m. When the valve located at the bottom is opened, the rate of change of water level (L) with respect to time (t) is, where k = 0.6 m s–3/2 The level of water (in m) in the tank at time 0.5 s after opening the valve is ____________ (rounded off to second decimal place).

Answer: (3.7 to 3.9)

Q. 26 – Q. 55 carry two marks each.

26. Match the equipment in Column A with the corresponding process in Column B

(A) P-I, Q-IV, R-II, S-III

(B) P-III, Q-IV, R-II, S-I

(C) P-IV, Q-I, R-II, S-III

(D) P-IV, Q-III, R-I, S-II

Answer: (B)

27. In the year 2005, the cost of a shell and tube heat exchanger with 68 m2 heat transfer area was Rs. 12.6 Lakh. Chemical Engineering Index for cost in 2005 was 509.4 and now the index is 575.4. Based on index of 0.6 for capacity scaling, the present cost (in Lakhs of rupees) of a similar heat exchanger having 100 m2 heat transfer area is estimated to be 

(A) 17.94

(B) 19.94

(C) 20.94

(D) 22.94

Answer: (A)

28. A furnace installed at a cost of Rs. 24 Lakh is expected to serve its useful life of 5 years. Salvage value of the furnace is Rs. 8 Lakh. The interest rate compounded annually is 8%. The estimated capitalized cost (in Lakhs of rupees) is

(A) 30

(B) 34.09

(C) 34.9

(D) 58.09

Answer: (D)

29. G denotes the Gibbs free energy of a binary mixture, nT denotes the total number of moles present in the system, μi is the chemical potential of the ith component (μi ≠ 0 and μ1 > μ2) and xi is the mole fraction of the ith component. The correct variation of G/nT (in J/mol) at constant temperature and pressure is given by

Answer: (C)

30. A person is drowning in sea at location R and the lifeguard is standing at location P. The beach boundary is straight and horizontal, as shown in the figure.

The lifeguard runs at a speed of VL and swims at a speed of VS. In order to reach to the drowning person in optimum time, the lifeguard should choose point Q such that

Answer: (D)

31. The decay ratio for a system having complex conjugate poles as is

(A) 7 × 10–1

(B) 8 × 10–2

(C) 9 × 10–3

(D) 10 × 10–4

Answer: (C)

32. Match the items in Column A with the items in Column B

Here, Φ denotes the phase shift, K1 and K2 the process gains, τ the time constant, and AR the amplitude ratio.

(A) P-II, Q-III, R-IV, S-I

(B) P-III, Q-II, R-IV, S-I

(C) P-I, Q-IV, R-II, S-III

(D) P-IV, Q-I, R-II, S-III

Answer: (D)

33. In a laboratory batch setup, reaction of P over a catalyst was studied at various temperatures. The reactions occurring are

P → 2Q ; P → R

At the end of one hour of operation, the batch contains xP, xQ and xR mole fractions of P, Q and R components, respectively. The mole fractions of product components (xQ and xR) were found to vary linearly with temperature as given in the figure.

If the yield of Q based on reactant P consumed (YQ) at 25°C was found to be 0.40, then the value of YQ at 60°C is ____________ (rounded off to second decimal place).

Answer: (0.40 to 0.40)

34. An insulated storage tank contains 1000 kg liquid of specific heat 10 kJ kg-1 K-1. The liquid is heated by saturated steam, condensing in a helical coil at a temperature of 180°C. The heat transfer area of the coil is 0.1 m2. If the overall heat transfer coefficient is constant at 1000 W m-2 K-1, then the time (in hours) required to raise the temperature of the liquid in the tank from 20°C to 80°C is ____________ (rounded off to second decimal place).

Answer: (12.75 to 13.25)

35. The wall of a pipe of radius 1 m is at a uniform temperature of 200°C, and is covered by insulation of thickness 0.1 m. The ambient air outside the insulated pipe is at 20°C and has heat transfer coefficient of 10 W m-2 K-1. The thermal conductivity of the insulation material is 0.05 W m-1 K-1. If the heat transfer occurs at steady state, the temperature (in°C) of the outer surface of insulation is __________ (rounded off to second decimal place).

Answer: (27.8 to 28.6)

36. Vapour bubbles are formed in the nucleate boiling regime at a frequency of 10 bubbles per second per nucleation site. There are 100 nucleation sites per m2 of heating area. The latent heat of vapourization and the density of vapour under the operating condition are 1000 kJ/kg and 1 kg/m3 respectively. The diameter of each bubble is 10-3 m. Assume that the entire heat supplied is used for vapour generation. The heat flux (in Watt per m2 of heating area) is ______________ (rounded off to third decimal place).

Answer: (0.51 to 0.54)

37. Under isothermal condition, a vertical tube of length L = 100 m contains a gas of molecular weight equal to 60. The pressure and temperature at the top of the tube are 100 kPa and 25°C respectively. Consider the universal gas constant and acceleration due to gravity as 8.314 J mol-1 K-1 and 9.81 m s-2 respectively. If the gas is ideal, the pressure (in kPa) at the bottom of the tube will be ____________ (rounded off to third decimal place).

Answer: (102.37 to 102.44)

38. At a shear rate of 10 s-1, the apparent viscosity of a non-Newtonian liquid was found to be 1 Pa s. At a shear rate of 100 s-1, the apparent viscosity of the same liquid was found to be 0.5 Pa s. If the liquid follows power law behavior, the apparent viscosity (in Pa s) at a shear stress of 10 N m-2 is _____________ (rounded off to two decimal place).

Answer: (0.98 to 1.02)

39. A CSTR and a PFR of equal volume are connected in series as shown below to carry out a first-order, isothermal, liquid phase reaction

The rate constant is 0.2 s-1. The space-time is 5 s for both the reactors. The overall fractional conversion of A is ____________ (rounded off to third decimal place).

Answer: (0.80 to 0.84)

40. T he elementary second-order liquid phase reaction A + B → C + D is carried out in an isothermal plug flow reactor of 2 m3 volume. The inlet volumetric flow rate is 10 m3/h. The initial concentrations of both A and B are 2 kmol/m3. The rate constant is given as 2.5 m3 kmol-1 h-1. The percentage conversion of A is ____________.

Answer: (50 to 50)

41. It is decided to extract A from a feed containing 20 mol% A and 80 mol% B in two ideal cross-current stages as shown below, using equal amount of pure solvent C in each stage.

Components B and C are immiscible. 60% of A in the feed is extracted in Stage 1. The equilibrium relation is given by Y* = 1.5 X where, 

X = moles of A per mole of B in raffinate

Y* = moles of A per mole of C in extract in equilibrium with raffinate

The mol % of A in raffinate from Stage 2 is __________ (rounded off to second decimal place).

Answer: (3.75 to 3.95)

42. A binary distillation column is designed by McCabe-Thiele method to get a distillate mole fraction of 0.9. The enriching section operating line has an intercept with y-axis at 0.3 mole fraction. The ratio of liquid to vapour molar flow rate in the enriching section is _____________ (rounded off to third decimal place).

Answer: (0.65 to 0.68)

43. A fiberboard sheet (1.5 m × 2.0 m × 15 mm) is being dried by suspending it horizontally in a current of hot, dry air. The edges are insulated so that drying takes place only from the top and bottom surfaces. The wet sheet weighing 16 kg with initial moisture content of 60% loses moisture at a constant rate of 1.25 × 10-5 kg m-2 s-1 until the moisture content falls to 30%. All moisture contents are on dry basis. The time required for drying during constant rate period (in hour) is _____________ (rounded off to third decimal place).

Answer: (11.0 to 11.3)

44. Consider the following transfer function: 

                  

where, the natural period of oscillation is in min. The amplitude ratio at a frequency of 0.5 rad/min is_____________ (rounded off to second decimal place).

Answer: (0.41 to 0.42)

45 For a closed-loop system, consider the following transfer functions:

process Gp(s), controller Gc(s), measuring device Gm(s), and final control element Gf(s)

The offset in the closed loop response due to a unit step change introduced in the set point of the output variable is ________.

Answer: (0.2 to 0.2)

46. If  then the value of  is ________

Answer: (0 to 0)

47. For the matrix if det stands for the determinant and AT is the transpose of A then the value of det( ATA) is ____________

Answer: (1 t0 1)

48. An azeotropic mixture of ethanol and water is to be separated in a distillation column using benzene as an entrainer. At the column operating conditions, two liquid phases are formed on a tray. The degree(s) of freedom of the system for the choice of intensive properties at equilibrium is(are) ___________

Answer: (1 to 1(or) 2 to 2)

49. The volume of liquid filled in a spherical storage tank of radius R is computed from height of liquid, h, in the outside tube (neglecting the volume of liquid in the outside tube) as 

The estimate of liquid height (in m) to store V = 30 m3 of water in R = 3 m tank, after performing ONE iteration of Secant method, using 1 m and 3 m as two initial guesses of liquid height is ______________ (rounded off to second decimal place).

Answer: (1.80 to 2.00)

50. In a closed piston-cylinder system, methane was observed to obey the following equation of state

P (V – nb) = nRT

where b = 0.029 m3/mol. The temperature and volume are 500°C and 5 m3 respectively for 100 moles of methane. At this state of the system, the isobaric rate of change of temperature with volume (in°C/m3) is __________ (rounded off to second decimal place).

Answer: (367 to 369)

51. A set of standard stainless steel pipes, each of internal diameter 26.65 mm and 6000 mm length, is used to make a plug flow reactor by joining them in series to carry out degradation of polyethylene. Seven such pipes are required to obtain a conversion of 66% at 450 K. The minimum number of standard 8000 mm long pipes of the same internal diameter to be procured for obtaining at least 66% conversion under the same reaction conditions is ___________.

Answer: (6 to 6)

52. Hydrogenation of benzene is to be carried out using Ni (density = 8910 kg/m3) as catalyst, cast in the form of non-porous hollow cylinders, as shown below. The reaction occurs on all the surfaces of the hollow cylinder. During an experiment, one such cylinder is suspended in the reactant stream. If the observed rate of reaction is 0.39 mol (m2 of catalyst surface)-1 min-1, then the rate of reaction in mol (kg of catalyst)-1 min-1 is _____________ (rounded off to three decimal places).

Answer: (0.034 to 0.043)

53. T he humidity of air at a dry-bulb temperature of 65°C is 0.025 kg water/kg dry air. The latent heat of vaporization of water at 0°C is 2500 kJ/kg. The psychrometric ratio of air is 0.95 kJ (kg dry air)-1 K-1. Considering 0°C as reference temperature, the enthalpy of air (in kJ/kg) at its adiabatic saturation temperature of 35°C is ___________ (rounded off to two decimal places).

Answer: (124 to 125)

54. In a roll crusher, rolls of diameter 1 m each are set in such a manner that minimum clearance between the crushing surfaces is 15 mm. If the angle of nip is 31o, the maximum diameter of the particle (in mm) which can be crushed is ____________ (rounded off to third decimal place).

Answer: (52 to 54)

55. A hot liquid is to be cooled in a 1-1 shell and tube heat exchanger from 80°C to 50°C. Cooling water enters the tube side at 30°C, and exits at 45°C. The properties of the liquids are constant. Also, the overall heat transfer coefficient is same for counter-current and cocurrent modes. The percentage saving in heat transfer area for counter-current option with respect to the area of co-current option is __________ (rounded off to third decimal place).

Answer: (26.5 to 27.5)

GATE Exam 2018 Civil Engineering (CE-2) Question Paper With Answer Key

Civil Engineering (CE-2)

General Aptitude (GA) Set-8

1. “ His face ___________ with joy when the solution of the puzzle was _______ to him.”

The words that best fill the blanks in the above sentence are

(A) shone, shown

(B) shone, shone

(C) shown, shone

(D) shown, shown

Answer: (A)

2. “ Although it does contain some pioneering ideas, one would hardly characterize the work as _________.”

The word that best fills the blank in the above sentence is

(A) innovative

(B) simple

(C) dull

(D) boring

Answer: (A)

3. where 𝑎, 𝑏, 𝑛 and 𝑚 are
natural numbers. What is the value of 

(A) 2𝑎2𝑏2

(B) 𝑎4𝑏4

(C) 𝑎𝑏(𝑎 + 𝑏)

(D) 𝑎2 + 𝑏2

Answer: (B)

4. A three-member committee has to be formed from a group of 9 people. How many such distinct committees can be formed?

(A) 27

(B) 72

(C) 81

(D) 84

Answer: (D)

5. For non-negative integers, 𝑎, 𝑏, 𝑐, what would be the value of 𝑎 + 𝑏 + 𝑐 if log 𝑎 + log 𝑏 + log 𝑐 = 0?

(A) 3

(B) 1

(C) 0

(D) −1

Answer: (A)

Q. 6 – Q. 10 carry two marks each.

6. In manufacturing industries, loss is usually taken to be proportional to the square of the deviation from a target. If the loss is Rs. 4900 for a deviation of 7 units, what would be the loss in Rupees for a deviation of 4 units from the target?

(A) 400

(B) 1200

(C) 1600

(D) 2800

Answer: (C)

7. A faulty wall clock is known to gain 15 minutes every 24 hours. It is synchronized to the correct time at 9 AM on 11th July. What will be the correct time to the nearest minute when the clock shows 2 PM on 15th July of the same year?

(A) 12:45 PM

(B) 12:58 PM

(C) 1:00 PM

(D) 2:00 PM

Answer: (B)

8. The annual average rainfall in a tropical city is 1000 mm. On a particular rainy day (24-hour period), the cumulative rainfall experienced by the city is shown in the graph. Over the 24-hour period, 50% of the rainfall falling on a rooftop, which had an obstructionfree area of 50 m2, was harvested into a tank. What is the total volume of water collected in the tank in liters?

(A) 25,000

(B) 18,750

(C) 7,500

(D) 3,125

Answer: (C)

9. Given that 𝑥 ≠ 𝑦 ≠ 𝑧, what is the value of the product 𝑃𝑄𝑅?

(A) 0

(B) 1

(C) 𝑥𝑦𝑧

(D) 10𝑥𝑦𝑧

Answer: (B)

10. Each of the letters in the figure below represents a unique integer from 1 to 9. The letters are positioned in the figure such that each of (A+B+C), (C+D+E), (E+F+G) and (G+H+K) is equal to 13. Which integer does E represent?

(A) 1

(B) 4

(C) 6

(D) 7

Answer: (B)

Civil Engineering (Set 2)

Q. 1 – Q. 25 carry one mark each.

1. The solution of the equation passing through the point (1,1) is

(A) x

(B) x2

(C) x -1

(D) x -2

Answer: (C)

2. The graph of a function f(x) is shown in the figure.

For f(x) to be a valid probability density function, the value of h is

(A) 1/3

(B) 2/3

(C) 1

(D) 3

Answer: (A)

3. A probability distribution with right skew is shown in the figure.

The correct statement for the probability distribution is

(A) Mean is equal to mode

(B) Mean is greater than median but less than mode

(C) Mean is greater than median and mode

(D) Mode is greater than median

Answer: (C)

4. All the members of the planar truss (see figure), have the same properties in terms of area of cross-section (A) and modulus of elasticity (E).

For the loads shown on the truss, the statement that correctly represents the nature of forces in the members of the truss is:

(A) There are 3 members in tension, and 2 members in compression

(B) There are 2 members in tension, 2 members in compression, and 1 zero-force member

(C) There are 2 members in tension, 1 member in compression, and 2 zero-force members

(D) There are 2 members in tension, and 3 zero-force members

Answer: (D)

5. The setting time of cement is determined using

(A) Le Chatelier apparatus

(B) Briquette testing apparatus

(C) Vicat apparatus

(D) Casagrande’s apparatus

Answer: (C)

6. A structural member subjected to compression, has both translation and rotation restrained at one end, while only translation is restrained at the other end. As per IS 456 : 2000, the effective length factor recommended for design is

(A) 0.50

(B) 0.65

(C) 0.70

(D) 0.80

Answer: (D)

7. A vertical load of 10 kN acts on a hinge located at a distance of L/4 from the roller support Q of a beam of length L (see figure).

The vertical reaction at support Q is

(A) 0.0 kN

(B) 2.5 kN

(C) 7.5 kN

(D) 10.0 kN

Answer: (A)

8. A flownet below a dam consists of 24 equipotential drops and 7 flow channels. The difference between the upstream and downstream water levels is 6 m. The length of the flow line adjacent to the toe of the dam at exit is 1 m. The specific gravity and void ratio of the soil below the dam are 2.70 and 0.70, respectively. The factor of safety against piping is

(A) 1.67

(B) 2.5

(C) 3.4

(D) 4

Answer: (D)

9. The contact pressure and settlement distribution for a footing are shown in the figure.

The figure corresponds to a

(A) rigid footing on granular soil

(B) flexible footing on granular soil

(C) flexible footing on saturated clay

(D) rigid footing on cohesive soil

Answer: (A)

10. Which one of the following statements is NOT correct?

(A) When the water content of soil lies between its liquid limit and plastic limit, the soil is said to be in plastic state.

(B) Boussinesq’s theory is used for the analysis of stratified soil.

(C) The inclination of stable slope in cohesive soil can be greater than its angle of internal friction.

(D) For saturated dense fine sand, after applying overburden correction, if the Standard Penetration Test value exceeds 15, dilatancy correction is to be applied.

Answer: (B)

11. The clay mineral, whose structural units are held together by potassium bond is

(A) Halloysite

(B) Illite

(C) Kaolinite

(D) Smectite

Answer: (B)

12. D upuit’s assumptions are valid for

(A) artesian aquifer

(B) confined aquifer

(C) leaky aquifer

(D) unconfined aquifer

Answer: (D)

13. For a given discharge in an open channel, there are two depths which have the same specific energy. These two depths are known as

(A) alternate depths

(B) critical depths

(C) normal depths

(D) sequent depths

Answer: (A)

14. As per IS 10500:2012, for drinking water in the absence of alternate source of water, the permissible limits for chloride and sulphate, in mg/L, respectively are

(A) 250 and 200

(B) 1000 and 400

(C) 200 and 250

(D) 500 and 1000

Answer: (B)

15. In the figures, Group I represents the atmospheric temperature profiles (P, Q, R and S) and Group II represents dispersion of pollutants from a smoke stack (1, 2, 3 and 4). In the figures of Group I, the dashed line represents the dry adiabatic lapse rate, whereas the horizontal axis represents temperature and the vertical axis represents the altitude.

The correct match is

(A) P-1, Q-2, R-3, S-4

(B) P-1, Q-2, R-4, S-3

(C) P-1, Q-4, R-3, S-2

(D) P-3, Q-1, R-2, S-4

Answer: (A)

16. Peak Hour Factor (PHF) is used to represent the proportion of peak sub-hourly traffic flow within the peak hour. If 15-minute sub-hours are considered, the theoretically possible range of PHF will be

(A) 0 to 1.0

(B) 0.25 to 0.75

(C) 0.25 to 1.0

(D) 0.5 to 1.0

Answer: (C)

17. As per IRC:37-2012, in order to control subgrade rutting in flexible pavements, the parameter to be considered is

(A) horizontal tensile strain at the bottom of bituminous layer

(B) vertical compressive strain on top of subgrade

(C) vertical compressive stress on top of granular layer

(D) vertical deflection at the surface of the pavement

Answer: (B)

Q.18 The initial concavity in the load-penetration curve of a CBR test is NOT due to 

(A) uneven top surface

(B) high impact at start of loading

(C) inclined penetration plunger

(D) soft top layer of soaked soil

Answer: (B)

19. Probability (up to one decimal place) of consecutively picking 3 red balls without replacement from a box containing 5 red balls and 1 white ball is ______

Answer: (0.5 to 0.5)

20. The quadratic equation 2x2 – 3x + 3 = 0 is to be solved numerically starting with an initial guess as x0 = 2. The new estimate of x after the first iteration using Newton-Raphson method is ______ 

Answer: (1 to 1)

21. As per IS 456 : 2000, the minimum percentage of tension reinforcement (up to two decimal places) required in reinforced-concrete beams of rectangular cross-section (considering effective depth in the calculation of area) using Fe500 grade steel is ______

Answer: (0.17 to 0.17)

22. A reinforced-concrete slab with effective depth of 80 mm is simply supported at two opposite ends on 230 mm thick masonry walls. The centre-to-centre distance between the walls is 3.3 m. As per IS 456 : 2000, the effective span of the slab (in m, up to two decimal places) is ______

Answer: (3.15 to 3.15)

23. A fillet weld is simultaneously subjected to factored normal and shear stresses of 120 MPa and 50 MPa, respectively. As per IS 800 : 2007, the equivalent stress (in MPa, up to two decimal places) is ______

Answer: (147.50 to 148.50)

24.  The intensity of irrigation for the Kharif season is 50% for an irrigation project with culturable command area of 50,000 hectares. The duty for the Kharif season is 1000 hectare/cumec. Assuming transmission loss of 10%, the required discharge (in cumec, up to two decimal places) at the head of the canal is ______

Answer: (27.00 to 28.00)

25.  A culvert is designed for a flood frequency of 100 years and a useful life of 20 years. The risk involved in the design of the culvert (in percentage, up to two decimal places) is ______

Answer: (17.50 to 18.50)

Q. 26 – Q. 55 carry two marks each.

26. The matrix has

(A) real eigenvalues and eigenvectors

(B) real eigenvalues but complex eigenvectors

(C) complex eigenvalues but real eigenvectors

(D) complex eigenvalues and eigenvectors

Answer: (D)

27. The Laplace transform F (s) of the exponential function, f(t) = eat when t ≥ 0, where a is a constant and (s – a) > 0, is

Answer: (B)

28. The rank of the following matrix is

(A) 1

(B) 2

(C) 3

(D) 4

Answer: (B)

29. Two rigid bodies of mass 5 kg and 4 kg are at rest on a frictionless surface until acted upon by a force of 36 N as shown in the figure. The contact force generated between the two bodies is

(A) 4.0 N

(B) 7.2 N

(C) 9.0 N

(D) 16.0 N

Answer: (D)

30. Four bolts P, Q, R and S of equal diameter are used for a bracket subjected to a load of 130 kN as shown in the figure.

The force in bolt P is

(A) 32.50 kN

(B) 69.32 kN

(C) 82.50 kN

(D) 119.32 kN

Answer: (B)

31. A singly-reinforced rectangular concrete beam of width 300 mm and effective depth 400 mm is to be designed using M25 grade concrete and Fe500 grade reinforcing steel. For the beam to be under-reinforced, the maximum number of 16 mm diameter reinforcing bars that can be provided is

(A) 3

(B) 4

(C) 5

(D) 6

Answer: (C)

32. A 3 m high vertical earth retaining wall retains a dry granular backfill with angle of internal friction of 30° and unit weight of 20 kN/m3. If the wall is prevented from yielding (no movement), the total horizontal thrust (in kN per unit length) on the wall is 

(A) 0

(B) 30

(C) 45

(D) 270

Answer: (C)

33. Three soil specimens (Soil 1, Soil 2 and Soil 3), each 150 mm long and 100 mm diameter, are placed in series in a constant head flow set-up as shown in the figure. Suitable screens are provided at the boundaries of the specimens to keep them intact. The values of coefficient of permeability of Soil 1, Soil 2 and Soil 3 are 0.01, 0.003 and 0.03 cm/s, respectively.

The value of h in the set-up is

(A) 0 mm

(B) 40 mm

(C) 255 mm

(D) 560 mm

Answer: (B)

34. In a 5 m wide rectangular channel, the velocity u distribution in the vertical direction y is given by u = 1.25y1/6. The distance y is measured from the channel bed. If the flow depth is 2 m, the discharge per unit width of the channel is

(A) 2.40 m3/s/m

(B) 2.80 m3/s/m

(C) 3.27 m3/s/m

(D) 12.02 m3/s/m

Answer: (A)

35. A car follows a slow moving truck (travelling at a speed of 10 m/s) on a two-lane two-way highway. The car reduces its speed to 10 m/s and follows the truck maintaining a distance of 16 m from the truck. On finding a clear gap in the opposing traffic stream, the car accelerates at an average rate of 4 m/s2, overtakes the truck and returns to its original lane.
When it returns to its original lane, the distance between the car and the truck is 16 m. The total distance covered by the car during this period (from the time it leaves its lane and subsequently returns to its lane after overtaking) is

(A) 64 m

(B) 72 m

(C) 128 m

(D) 144 m

Answer: (B)

36. A level instrument at a height of 1.320 m has been placed at a station having a Reduced Level (RL) of 112.565 m. The instrument reads –2.835 m on a levelling staff held at the bottom of a bridge deck. The RL (in m) of the bottom of the bridge deck is

(A) 116.720

(B) 116.080

(C) 114.080

(D) 111.050

Answer: (A)

37. The value (up to two decimal places) of a line integral along C which is a straight line joining (0,0) to (1,1) is ______

Answer: (0.60 to 0.70)

38. An 8 m long simply-supported elastic beam of rectangular cross-section (100 mm × 200 mm) is subjected to a uniformly distributed load of 10 kN/m over its entire span. The maximum principal stress (in MPa, up to two decimal places) at a point located at the extreme compression edge of a cross-section and at 2 m from the support is ______

Answer: (0.0 to 0.0)

39. A prismatic beam P-Q-R of flexural rigidity EI = 1 × 104 kNm2 is subjected to a moment of 180 kNm at Q as shown in the figure.

The rotation at Q (in rad, up to two decimal places) is ______

Answer: (0.01 to 0.01 (or) ‐0.01 to ‐0.01)

40. A prismatic propped cantilever beam of span L and plastic moment capacity Mp is subjected to a concentrated load at its mid-span. If the collapse load of the beam is the value of α is ______

Answer: (6.0 to 6.0)

41. A 6 m long simply-supported beam is prestressed as shown in the figure.

The beam carries a uniformly distributed load of 6 kN/m over its entire span. If the effective flexural rigidity EI = 2 × 104 kN/m2 and the effective prestressing force is 200 kN, the net increase in length of the prestressing cable (in mm, up to two decimal places) is ______

Answer: (0.10 to 0.12)

42. A cable PQ of length 25 m is supported at two ends at the same level as shown in the figure. The horizontal distance between the supports is 20 m. A point load of 150 kN is applied at point R which divides it into two equal parts.

Neglecting the self-weight of the cable, the tension (in kN, in integer value) in the cable due to the applied load will be ______

Answer: (125 to 125)

43. The compression curve (void ratio, e vs. effective stress, σ′v) for a certain clayey soil is a straight line in a semi-logarithmic plot and it passes through the points (e = 1.2; σ′= 50 kPa) and (e = 0.6; σ′= 800 kPa). The compression index (up to two decimal places) of the soil is ______

Answer: (0.45 to 0.55)

44. The total horizontal and vertical stresses at a point X in a saturated sandy medium are 170 kPa and 300 kPa, respectively. The static pore-water pressure is 30 kPa. At failure, the excess pore-water pressure is measured to be 94.50 kPa, and the shear stresses on the vertical and horizontal planes passing through the point X are zero. Effective cohesion is 0 kPa and effective angle of internal friction is 36°. The shear strength (in kPa, up to two decimal places) at point X is ______

Answer: (51.50 to 53.50)

45. A group of nine piles in a 3 × 3 square pattern is embedded in a soil strata comprising dense sand underlying recently filled clay layer, as shown in the figure. The perimeter of an individual pile is 126 cm. The size of pile group is 240 cm × 240 cm. The recently filled clay has undrained shear strength of 15 kPa and unit weight of  16 kN/m3.

The negative frictional load (in kN, up to two decimal places) acting on the pile group is ______

Answer: (472.00 to 472.50)

46. A three-fluid system (immiscible) is connected to a vacuum pump. The specific gravity values of the fluids (S1, S2) are given in the figure.

The gauge pressure value (in kN/m2, up to two decimal places) of 𝑝1 is ______

Answer: (-.90 to -8.0)

47. The total rainfall in a catchment of area 1000 km2, during a 6 h storm, is 19 cm. The surface runoff due to this storm computed from triangular direct runoff hydrograph is 1×108 m3. The Φindex for this storm (in cm/h, up to one decimal place) is ______

Answer: (1.50 to 1.50)

48. A rough pipe of 0.5 m diameter, 300 m length and roughness height of 0.25 mm, carries water (kinematic viscosity = 0.9 × 10–6 m2/s) with velocity of 3 m/s. Friction factor (f) for laminar flow is given by f = 64/Re, and for turbulent flow it is given by Re = Reynolds number, r = radius of pipe, k = roughness height and g = 9.81 m/s2. The head loss (in m, up to three decimal places) in the pipe due to friction is ______

Answer: (4.50 to 4.70)

49. A flocculation tank contains 1800 m3 of water, which is mixed using paddles at an average velocity gradient G of 100/s. The water temperature and the corresponding dynamic viscosity are 30°C and 0.798 × 10-3 Ns/m2, respectively. The theoretical power required to achieve the stated value of G (in kW, up to two decimal places) is ______

Answer: (14.00 to 15.00)

50. A coal containing 2% sulfur is burned completely to ash in a brick kiln at a rate of 30 kg/min. The sulfur content in the ash was found to be 6% of the initial amount of sulfur present in the coal fed to the brick kiln. The molecular weights of S, H and O are 32, 1 and 16 g/mole, respectively. The annual rate of sulfur dioxide (SO2) emission from the kiln (in tonnes/year, up to two decimal places) is ______

Answer: (590.00 to 595.00)

51. At a small water treatment plant which has 4 filters, the rates of filtration and backwashing are 200 m3/d/m2 and 1000 m3/d/m2, respectively. Backwashing is done for 15 min per day. The maturation, which occurs initially as the filter is put back into service after cleaning, takes 30 min. It is proposed to recover the water being wasted during backwashing and maturation. The percentage increase in the filtered water produced (up to two decimal places) would be ______

Answer: (7.75 to 7.95)

52. A schematic flow diagram of a completely mixed biological reactor with provision for recycling of solids is shown in the figure.

S0, S = readily biodegradable soluble BOD, mg/L
Q, Qr, Qw = flow rates, m3/d
X0, X, Xe, Xu = microorganism concentrations (mixed-liquor volatile suspended solids or MLVSS), mg/L

The mean cell residence time (in days, up to one decimal place) is ______

Answer: (7.5 to 7.5)

53. The space mean speed (kmph) and density (vehicles/km) of a traffic stream are linearly related. The free flow speed and jam density are 80 kmph and 100 vehicles/km respectively. The traffic flow (in vehicles/h, up to one decimal place) corresponding to a speed of 40 kmph is ______

Answer: (2000.0 to 2000.0)

54. A 7.5 m wide two-lane road on a plain terrain is to be laid along a horizontal curve of radius 510 m. For a design speed of 100 kmph, super-elevation is provided as per IRC: 73- 1980. Consider acceleration due to gravity as 9.81 m/s2. The level difference between the inner and outer edges of the road (in m, up to three decimal places) is ______

Answer: (0.520 to 0.530)

55. An aerial photograph of a terrain having an average elevation of 1400 m is taken at a scale of 1:7500. The focal length of the camera is 15 cm. The altitude of the flight above mean sea level (in m, up to one decimal place) is ______

Answer: (2520.0 to 2530.0)

GATE Exam 2018 Civil Engineering (CE-1) Question Paper With Answer Key

Civil Engineering CE-1

General Aptitude (GA) Set-7

Q. 1 – Q. 5 carry one mark each.

1. “ The driver applied the _______ as soon as she approached the hotel where she wanted to take a ________.”

The words that best fill the blanks in the above sentence are

(A) brake, break

(B) break, break

(C) brake, brake

(D) break, brake

Answer: (A)

2. “ It is no surprise that every society has had codes of behaviour; however, the nature of these codes is often _________.”

The word that best fills the blank in the above sentence is

(A) unpredictable

(B) simple

(C) expected

(D) strict

Answer: (A)

3. Hema’s age is 5 years more than twice Hari’s age. Suresh’s age is 13 years less than 10 times Hari’s age. If Suresh is 3 times as old as Hema, how old is Hema?

(A) 14

(B) 17

(C) 18

(D) 19

Answer: (D)

4. Tower A is 90 m tall and tower B is 140 m tall. They are 100 m apart. A horizontal skywalk connects the floors at 70 m in both the towers. If a taut rope connects the top of tower A to the bottom of tower B, at what distance (in meters) from tower A will the rope intersect the skywalk?

(A) 22.22

(B) 50

(C) 57.87

(D) 77.78

Answer: (Marks to All)

5.  The temperature 𝑇 in a room varies as a function of the outside temperature 𝑇0 and the number of persons in the room 𝑝, according to the relation 𝑇 = Κ (Θ𝑝 + 𝑇0), where Θ and Κ are constants. What would be the value of Θ given the following data?

(A) 0.8

(B) 1.0

(C) 2.0

(D) 10.0

Answer: (B)

Q. 6 – Q. 10 carry two marks each.

6. A fruit seller sold a basket of fruits at 12.5% loss. Had he sold it for Rs. 108 more, he would have made a 10% gain. What is the loss in Rupees incurred by the fruit seller?

(A) 48

(B) 52

(C) 60

(D) 108

Answer: (C)

7. The price of a wire made of a superalloy material is proportional to the square of its length. The price of 10 m length of the wire is Rs. 1600. What would be the total price (in Rs.) of two wires of lengths 4 m and 6m?

(A) 768

(B) 832

(C) 1440

(D) 1600

Answer: (B)

8. Which of the following function(s) is an accurate description of the graph for the range(s) indicated?

(i) 𝑦 = 2𝑥 + 4 for −3 ≤ 𝑥 ≤ −1

(ii) 𝑦 = |𝑥 − 1| for −1 ≤ 𝑥 ≤ 2

(iii) 𝑦 = ||𝑥| − 1| for −1 ≤ 𝑥 ≤ 2

(iv) 𝑦 = 1 for 2 ≤ 𝑥 ≤ 3

(A) (i), (ii) and (iii) only.

(B) (i), (ii) and (iv) only.

(C) (i) and (iv) only.

(D) (ii) and (iv) only.

Answer: (B)

9. Consider a sequence of numbers 𝑎1, 𝑎2, 𝑎3, ⋯ , 𝑎𝑛 where for each integer 𝑛 > 0. What is the sum of the first 50 terms?

(A) 

(B) 

(C) 

(D) 

Answer: (C)

10. Each of the letters arranged as below represents a unique integer from 1 to 9. The letters are positioned in the figure such that (A × B × C), (B × G × E) and (D × E × F) are equal. Which integer among the following choices cannot be represented by the letters A, B, C, D, E, F or G?

(A) 4

(B) 5

(C) 6

(D) 9

Answer: (B)

Civil Engineering (Set 1)

Q. 1 – Q. 25 carry one mark each.

1. Which one of the following matrices is singular?

Answer: (C)

2. For the given orthogonal matrix Q, 

The inverse is

Answer: (C)

3. At the point 𝑥 = 0, the function 𝑓(𝑥) = 𝑥3 has

(A) local maximum

(B) local minimum

(C) both local maximum and minimum

(D) neither local maximum nor local minimum

Answer: (D)

4. A column of height h with a rectangular cross-section of size a×2a has a buckling load of P. If the cross-section is changed to 0.5a × 3a and its height changed to 1.5h, the buckling load of the redesigned column will be

(A) P/12

(B) P/4

(C) P/2

(D) 3P/4

Answer: (A)

5. A steel column of ISHB 350 @72.4 kg/m is subjected to a factored axial compressive load of 2000 kN. The load is transferred to a concrete pedestal of grade M20 through a square base plate. Consider bearing strength of concrete as 0.45fck, where fck is the characteristic strength of concrete. Using limit state method and neglecting the self weight of base plate and steel column, the length of a side of the base plate to be provided is 

(A) 39 cm

(B) 42 cm

(C) 45 cm

(D) 48 cm

Answer: (D)

6. The Le Chatelier apparatus is used to determine

(A) compressive strength of cement

(B) fineness of cement

(C) setting time of cement

(D) soundness of cement

Answer: (D)

7. The deformation in concrete due to sustained loading is

(A) creep

(B) hydration

(C) segregation

(D) shrinkage

Answer: (A)

8. A solid circular beam with radius of 0.25 m and length of 2 m is subjected to a twisting moment of 20 kNm about the z-axis at the free end, which is the only load acting as shown in the figure. The shear stress component 𝜏𝑥𝑦 at Point ‘M’ in the cross-section of the beam at a distance of 1 m from the fixed end is

(A) 0.0 MPa

(B) 0.51 MPa

(C) 0.815 MPa

(D) 2.0 MPa

Answer: (A)

9. Two rectangular under-reinforced concrete beam sections X and Y are similar in all aspects except that the longitudinal compression reinforcement in section Y is 10% more. Which one of the following is the correct statement?

(A) Section X has less flexural strength and is less ductile than section Y

(B) Section X has less flexural strength but is more ductile than section Y

(C) Sections X and Y have equal flexural strength but different ductility

(D) Sections X and Y have equal flexural strength and ductility

Answer: (C)

10. The percent reduction in the bearing capacity of a strip footing resting on sand under flooding condition (water level at the base of the footing) when compared to the situation where the water level is at a depth much greater than the width of footing, is approximately 

(A) 0

(B) 25

(C) 50

(D) 100

Answer: (C)

11. The width of a square footing and the diameter of a circular footing are equal. If both the footings are placed on the surface of sandy soil, the ratio of the ultimate bearing capacity of circular footing to that of square footing will be

(A) 4/3

(B) 1

(C) 3/4

(D) 2/3

Answer: (C)

12. Bernoulli’s equation is applicable for

(A) viscous and compressible fluid flow

(B) inviscid and compressible fluid flow

(C) inviscid and incompressible fluid flow

(D) viscous and incompressible fluid flow

Answer: (C)

13. There are 20,000 vehicles operating in a city with an average annual travel of 12,000 km per vehicle. The NOx emission rate is 2.0 g/km per vehicle. The total annual release of NOx will be

(A) 4,80,000 kg

(B) 4,800 kg

(C) 480 kg

(D) 48 kg

Answer: (A)

14. A bitumen sample has been graded as VG30 as per IS : 73-2013. The ‘30’ in the grade means that

(A) penetration of bitumen at 25°C is between 20 and 40

(B) viscosity of bitumen at 60°C is between 2400 and 3600 Poise

(C) ductility of bitumen at 27°C is more than 30 cm

(D) elastic recovery of bitumen at 15°C is more than 30%

Answer: (B)

15. The speed-density relationship for a road section is shown in the figure.

The shape of the flow-density relationship is

(A) piecewise linear

(B) parabolic

(C) initially linear then parabolic

(D) initially parabolic then linear

Answer: (C)

16. A well-designed signalized intersection is one in which the

(A) crossing conflicts are increased

(B) total delay is minimized

(C) cycle time is equal to the sum of red and green times in all phases

(D) cycle time is equal to the sum of red and yellow times in all phases

Answer: (B)

17. A flow field is given by 𝑢 = 𝑦2, 𝑣 = −𝑥𝑦, 𝑤 = 0. Value of the z-component of the angular velocity (in radians per unit time, up to two decimal places) at the point (0, −1, 1) is ______

Answer: (1.50 to 1.50)

18. The frequency distribution of the compressive strength of 20 concrete cube specimens is given in the table.

If 𝜇 is the mean strength of the specimens and 𝜎 is the standard deviation, the number of specimens (out of 20) with compressive strength less than 𝜇 − 3𝜎 is ______

Answer: (0 to 0)

19. In a fillet weld, the direct shear stress and bending tensile stress are 50 MPa and 150 MPa, respectively. As per IS 800: 2007, the equivalent stress (in MPa, up to two decimal places) will be ______

Answer: (173.10 to 173.30)

20. In a shrinkage limit test, the volume and mass of a dry soil pat are found to be 50 cm3 and 88 g, respectively. The specific gravity of the soil solids is 2.71 and the density of water is 1 g/cc. The shrinkage limit (in %, up to two decimal places) is ______

Answer: (19.50 to 20.50)

21. A core cutter of 130 mm height has inner and outer diameters of 100 mm and 106 mm, respectively. The area ratio of the core cutter (in %, up to two decimal places) is ______

Answer: (12.30 to 12.40)

22. A 1:50 model of a spillway is to be tested in the laboratory. The discharge in the prototype spillway is 1000 m3/s. The corresponding discharge (in m3/s, up to two decimal places) to be maintained in the model, neglecting variation in acceleration due to gravity, is ______

Answer: (0.05 to 0.06)

23. A 10 m wide rectangular channel carries a discharge of 20 m3/s under critical condition. Using g = 9.81 m/s2, the specific energy (in m, up to two decimal places) is ______

Answer: (1.10 to 1.20)

24. For routing of flood in a given channel using the Muskingum method, two of the routing coefficients are estimated as C0 = –0.25 and C1 = 0.55. The value of the third coefficient C2 would be ______

Answer: (0.70 to 0.70)

25. A city generates 40×106 kg of municipal solid waste (MSW) per year, out of which only 10% is recovered/recycled and the rest goes to landfill. The landfill has a single lift of 3 m height and is compacted to a density of 550 kg/m3. If 80% of the landfill is assumed to be MSW, the landfill area (in m2, up to one decimal place) required would be ______

Answer: (27271 to 27274)

Q. 26 – Q. 55 carry two marks each.

26. The value of the integral 

(A) π2/8

(B) π2/4

(C) π2/2

(D) π2

Answer: (B)

27. A cantilever beam of length 2 m with a square section of side length 0.1 m is loaded vertically at the free end. The vertical displacement at the free end is 5 mm. The beam is made of steel with Young’s modulus of 2.0×1011 N/m2. The maximum bending stress at the fixed end of the cantilever is

(A) 20.0 MPa

(B) 37.5 MPa

(C) 60.0 MPa

(D) 75.0 MPa

Answer: (B)

28. A cylinder of radius 250 mm and weight, W = 10 kN is rolled up an obstacle of height 50 mm by applying a horizontal force P at its centre as shown in the figure.

All interfaces are assumed frictionless. The minimum value of P is

(A) 4.5 kN

(B) 5.0 kN

(C) 6.0 kN

(D) 7.5 kN

Answer: (D)

29. A plate in equilibrium is subjected to uniform stresses along its edges with magnitude 𝜎𝑥𝑥 = 30 MPa and 𝜎𝑦𝑦 = 50 MPa as shown in the figure.

The Young’s modulus of the material is 2×1011 N/m2 and the Poisson’s ratio is 0.3. If 𝜎𝑧𝑧 is negligibly small and assumed to be zero, then the strain 𝜀𝑧𝑧 is

(A) -120×10-6

(B) – 60×10-6

(C) 0.0

(D) 120 ×10-6

Answer: (A)

30. The figure shows a simply supported beam PQ of uniform flexural rigidity EI carrying two moments M and 2M.

The slope at P will be

(A) 0

(B) ML/(9EI)

(C) ML/(6EI)

(D) ML/(3EI)

Answer: (C)

31. A 0.5 m × 0.5 m square concrete pile is to be driven in a homogeneous clayey soil having undrained shear strength, cu = 50 kPa and unit weight, γ = 18.0 kN/m3. The design capacity of the pile is 500 kN. The adhesion factor α is given as 0.75. The length of the pile required for the above design load with a factor of safety of 2.0 is

(A) 5.2 m

(B) 5.8 m

(C) 11.8 m

(D) 12.5 m

Answer: (C)

32. A closed tank contains 0.5 m thick layer of mercury (specific gravity = 13.6) at the bottom. A 2.0 m thick layer of water lies above the mercury layer. A 3.0 m thick layer of oil (specific gravity = 0.6) lies above the water layer. The space above the oil layer contains air under pressure. The gauge pressure at the bottom of the tank is 196.2 kN/m2. The density of water is 1000 kg/m3 and the acceleration due to gravity is 9.81 m/s2. The value of pressure in the air space is

(A) 92.214 kN/m2

(B) 95.644 kN/m2

(C) 98.922 kN/m2

(D) 99.321 kN/m2

Answer: (A)

33. A rapid sand filter comprising a number of filter beds is required to produce 99 MLD of potable water. Consider water loss during backwashing as 5%, rate of filtration as 6.0 m/h and length to width ratio of filter bed as 1.35. The width of each filter bed is to be kept equal to 5.2 m. One additional filter bed is to be provided to take care of break-down,repair and maintenance. The total number of filter beds required will be 

(A) 19

(B) 20

(C) 21

(D) 22

Answer: (C or D)

34. A priority intersection has a single-lane one-way traffic road crossing an undivided twolane two-way traffic road. The traffic stream speed on the single-lane road is 20 kmph and the speed on the two-lane road is 50 kmph. The perception-reaction time is 2.5 s, coefficient of longitudinal friction is 0.38 and acceleration due to gravity is 9.81 m/s2. A clear sight triangle has to be ensured at this intersection. The minimum lengths of the sides of the sight triangle along the two-lane road and the single-lane road, respectively will be 

(A) 50 m and 20 m

(B) 61 m and 18 m

(C) 111 m and 15 m

(D) 122 m and 36 m

Answer: (C)

35. The following details refer to a closed traverse:

The length and direction (whole circle bearing) of closure, respectively are

(A) 1 m and 90°

(B) 2 m and 90°

(C) 1 m and 270°

(D) 2 m and 270°

Answer: (A or C)

36. A square area (on the surface of the earth) with side 100 m and uniform height, appears as 1 cm2 on a vertical aerial photograph. The topographic map shows that a contour of 650 m passes through the area. If focal length of the camera lens is 150 mm, the height from which the aerial photograph was taken, is

(A) 800 m

(B) 1500 m

(C) 2150 m

(D) 3150 m

Answer: (C)

37. T he solution at 𝑥 = 1, 𝑡 = 1 of the partial differential equation subject to initial conditions of 𝑢(0) = 3𝑥 and is ______

(A) 1

(B) 2

(C) 4

(D) 6

Answer: (D)

38. The solution (up to three decimal places) at 𝑥 = 1 of the differential equation  subject to boundary conditions is ______

Answer: (0.36 to 0.37)

39. Variation of water depth (𝑦) in a gradually varied open channel flow is given by the first order differential equation

Given initial condition: 𝑦(𝑥 = 0) = 0.8 𝑚. The depth (in m, up to three decimal places) of flow at a downstream section at x = 1 m from one calculation step of Single Step Euler Method is ______

Answer: (0.78 to 0.80)

40. An RCC short column (with lateral ties) of rectangular cross section of 250 mm × 300 mm is reinforced with four numbers of 16 mm diameter longitudinal bars. The grades of steel and concrete are Fe415 and M20, respectively. Neglect eccentricity effect. Considering limit state of collapse in compression (IS 456 : 2000), the axial load carrying capacity of the column (in kN, up to one decimal place), is ______

Answer: (815 to 830 (or) 905 to 920)

41. An RCC beam of rectangular cross section has factored shear of 200 kN at its critical section. Its width b is 250 mm and effective depth d is 350 mm. Assume design shear strength 𝜏𝑐 of concrete as 0.62 N/mm2 and maximum allowable shear stress 𝜏𝑐,𝑚𝑎𝑥 in concrete as 2.8 N/mm2. If two legged 10 mm diameter vertical stirrups of Fe250 grade steel are used, then the required spacing (in cm, up to one decimal place) as per limit state method will be ______

Answer: (7.0 to 9.0)

42. The dimensions of a symmetrical welded I-section are shown in the figure.

The plastic section modulus about the weaker axis (in cm3, up to one decimal place) is ______

Answer: (88.0 to 92.0)

43. Consider the deformable pin-jointed truss with loading, geometry and section properties as shown in the figure.

Given that E = 2×1011 N/m2, A = 10 mm2, L = 1 m and P = 1 kN. The horizontal displacement of Joint C (in mm, up to one decimal place) is ______

Answer: (2.60 to 2.80)

44. At a construction site, a contractor plans to make an excavation as shown in the figure.

The water level in the adjacent river is at an elevation of +20.0 m. Unit weight of water is 10 kN/m3. The factor of safety (up to two decimal places) against sand boiling for the proposed excavation is ______

Answer: (1.00 to 1.03)

45. A conventional drained triaxial compression test was conducted on a normally consolidated clay sample under an effective confining pressure of 200 kPa. The deviator stress at failure was found to be 400 kPa. An identical specimen of the same clay sample is isotropically consolidated to a confining pressure of 200 kPa and subjected to standard undrained triaxial compression test. If the deviator stress at failure is 150 kPa, the pore pressure developed (in kPa, up to one decimal place) is ______

Answer: (124 to 126)

46. The void ratio of a soil is 0.55 at an effective normal stress of 140 kPa. The compression index of the soil is 0.25. In order to reduce the void ratio to 0.4, an increase in the magnitude of effective normal stress (in kPa, up to one decimal place) should be ______

Answer: (416.0 to 420.0)

47. A rigid smooth retaining wall of height 7 m with vertical backface retains saturated clay as backfill. The saturated unit weight and undrained cohesion of the backfill are 17.2 kN/mand 20 kPa, respectively. The difference in the active lateral forces on the wall (in kN per meter length of wall, up to two decimal places), before and after the occurrence of tension
cracks is ______

Answer: (45 to 49 or -49 to -45)

48. Rainfall depth over a watershed is monitored through six number of well distributed rain gauges. Gauged data are given below

The Thiessen mean value (in mm, up to one decimal place) of the rainfall is ______

Answer: (478.5 to 479.5)

49. The infiltration rate 𝑓 in a basin under ponding condition is given by 𝑓 = 30 + 10𝑒−2𝑡, where, 𝑓 is in mm/h and t is time in hour. Total depth of infiltration (in mm, up to one decimal place) during the last 20 minutes of a storm of 30 minutes duration is ______

Answer: (11.0 to 12.0)

50. I n a laboratory, a flow experiment is performed over a hydraulic structure. The measured values of discharge and velocity are 0.05 m3/s and 0.25 m/s, respectively. If the full scale structure (30 times bigger) is subjected to a discharge of 270 m3/s, then the time scale (model to full scale) value (up to two decimal places) is ______

Answer: (0.15 to 0.25)

51. A water sample analysis data is given below

The carbonate hardness (expressed as mg/L of CaCO3, up to one decimal place) for the water sample is ______

Answer: (272.0 to 274.0)

52. T he ultimate BOD (𝐿0) of a wastewater sample is estimated as 87% of COD. The COD of this wastewater is 300 mg/L. Considering first order BOD reaction rate constant k (use natural log) = 0.23 per day and temperature coefficient θ = 1.047, the BOD value (in mg/L, up to one decimal place) after three days of incubation at 27°C for this wastewater will be
______

Answer: (154.0 to 161.0)

53. A waste activated sludge (WAS) is to be blended with green waste (GW). The carbon (C) and nitrogen (N) contents, per kg of WAS and GW, on dry basis are given in the table.

The ratio of WAS to GW required (up to two decimal places) to achieve a blended C:N ratio of 20:1 on dry basis is ______

Answer: (1.60 to 1.70)

54. Given the following data: design life n = 15 years, lane distribution factor D = 0.75, annual rate of growth of commercial vehicles r = 6%, vehicle damage factor F = 4 and initial traffic in the year of completion of construction = 3000 Commercial Vehicles Per Day (CVPD). As per IRC:37-2012, the design traffic in terms of cumulative number of standard axles (in million standard axles, up to two decimal places) is ______

Answer: (75.00 to 78.00)

55. A n aircraft approaches the threshold of a runway strip at a speed of 200 km/h. The pilot decelerates the aircraft at a rate of 1.697 m/s2 and takes 18 s to exit the runway strip. If the deceleration after exiting the runway is 1 m/s2, then the distance (in m, up to one decimal place) of the gate position from the location of exit on the runway is ______

Answer: (311.0 to 319.0)

GATE Exam 2018 Biotechnology (BT) Question Paper With Answer Key

Biotechnology

General Aptitude (GA) Set-4

Q. 1 – Q. 5 carry one mark each.

1. “ When she fell down the _______, she received many _______ but little help.”

The words that best fill the blanks in the above sentence are

(A) stairs, stares

(B) stairs, stairs

(C) stares, stairs

(D) stares, stares

Answer: (A)

2.  “ In spite of being warned repeatedly, he failed to correct his _________ behaviour.”

The word that best fills the blank in the above sentence is

(A) rational

(B) reasonable

(C) errant

(D) good

Answer: (C)

3. For 0 ≤ 𝑥 ≤ 2𝜋, sin 𝑥 and cos 𝑥 are both decreasing functions in the interval ________.

(A) 

(B) 

(C) 

(D) 

Answer: (B)

4. The area of an equilateral triangle is √3. What is the perimeter of the triangle?

(A) 2

(B) 4

(C) 6

(D) 8

Answer: (C)

5. Arrange the following three-dimensional objects in the descending order of their volumes:

(i) A cuboid with dimensions 10 cm, 8 cm and 6 cm

(ii) A cube of side 8 cm

(iii) A cylinder with base radius 7 cm and height 7 cm

(iv) A sphere of radius 7 cm

(A) (i), (ii), (iii), (iv)

(B) (ii), (i), (iv), (iii)

(C) (iii), (ii), (i), (iv)

(D) (iv), (iii), (ii), (i)

Answer: (D)

Q. 6 – Q. 10 carry two marks each.

6. An automobile travels from city A to city B and returns to city A by the same route. The speed of the vehicle during the onward and return journeys were constant at 60 km/h and 90 km/h, respectively. What is the average speed in km/h for the entire journey?

(A) 72

(B) 73

(C) 74

(D) 75

Answer: (A)

7. A set of 4 parallel lines intersect with another set of 5 parallel lines. How many parallelograms are formed?

(A) 20

(B) 48

(C) 60

(D) 72

Answer: (C)

8. To pass a test, a candidate needs to answer at least 2 out of 3 questions correctly. A total of 6,30,000 candidates appeared for the test. Question A was correctly answered by 3,30,000 candidates. Question B was answered correctly by 2,50,000  candidates. Question C was answered correctly by 2,60,000 candidates. Both questions A and B were answered correctly by 1,00,000 candidates. Both questions B and C were answered correctly by 90,000 candidates. Both questions A and C were answered correctly by 80,000 candidates. If the number of students answering all questions correctly is the same as the number answering none, how many candidates failed to clear the test?

(A) 30,000

(B) 2,70,000

(C) 3,90,000

(D) 4,20,000

Answer: (D)

9. If 𝑥2 + 𝑥 − 1 = 0 what is the value of 

(A) 1

(B) 5

(C) 7

(D) 9

Answer: (C)

10. In a detailed study of annual crow births in India, it was found that there was relatively no growth during the period 2002 to 2004 and a sudden spike from 2004 to 2005. In another unrelated study, it was found that the revenue from cracker sales in India which remained fairly flat from 2002 to 2004, saw a sudden spike in 2005 before declining again in 2006. The solid line in the graph below refers to annual sale of crackers and the dashed line refers to the annual crow births in India. Choose the most appropriate inference from the above data.

(A) There is a strong correlation between crow birth and cracker sales.

(B) Cracker usage increases crow birth rate.

(C) If cracker sale declines, crow birth will decline.

(D) Increased birth rate of crows will cause an increase in the sale of crackers.

Answer: (A)

Biotechnology

Q. 1 – Q. 25 carry one mark each.

1. Consider an unfair coin. The probability of getting heads is 0.6. If you toss this coin twice, what is the probability that the first or the second toss is heads?

(A) 0.56

(B) 0.64

(C) 0.84

(D) 0.96

Answer: (C)

2. If serum is removed from the growth medium of human embryonic kidney cell line (HEK), then the cells will

(A) proliferate faster

(B) proliferate normally

(C) undergo cell cycle arrest

(D) undergo immediate apoptosis

Answer: (C)

3. The repeat sequence of telomere in humans is

(A) 5′-TATAAT-3′

(B) 5′-TTAGGG-3′

(C) 5′-GGGCCC-3′

(D) 5′-AAAAAA-3′

Answer: (B)

4. If a segment of a sense strand of DNA is 5-ATGGACCAGA-3, then the resulting RNA sequence after transcription is

(A) 5′-AGACCAGGTA-3′

(B) 5′-UCUGGUCCAU-3′

(C) 5′-UACCUGGUCU-3′

(D) 5′-AUGGACCAGA-3′

Answer: (D)

5. Which one of the following is an example of a neurotoxin?

(A) Cholera toxin

(B) Streptolysin-O

(C) Botulinum toxin

(D) Diphtheria toxin

Answer: (C)

6. Which of the following components constitute a molecular mechanics force field?

P. Bond stretching

Q. Bond angle bending

R. Torsional bond rotation

S. Non-bonded interactions

(A) P and Q only

(B) P, Q and R only

(C) P, Q and S only

(D) P, Q, R and S

Answer: (D)

7. Which one of the following BLAST search programs is used to identify homologs of a genomic DNA query in a protein sequence database?

(A) blastp

(B) blastn

(C) blastx

(D) tblastn

Answer: (C)

8. A mixture contains three similarly sized peptides P, Q and R. The peptide P is positively charged, Q is weakly negative and R is strongly negative. If this mixture is passed through an ion-exchange chromatography column containing an anionic resin, their order of elution will be

(A) P, Q, R

(B) R, Q, P

(C) Q, R, P

(D) P, Q and R elute together

Answer: (B)

9. Which one of the following is INCORRECT about protein structures?

(A) A protein fold is stabilized by favorable non-covalent interactions

(B) All parts of a fold can be classified as helices, strands or turns

(C) Two non-covalent atoms cannot be closer than the sum of their van der Waals radii

(D) The peptide bond is nearly planar

Answer: (B)

10. Which one of the following metabolic processes in mammalian cells does NOT occur in the mitochondria?

(A) Citric acid cycle

(B) Oxidative phosphorylation

(C) Fatty acid β-oxidation

(D) Glycolysis

Answer: (D)

11. Which one of the following is NOT a principal component of innate immunity?

(A) Mucosal epithelia

(B) Dendritic cells

(C) Complement system

(D) Memory B-cells

Answer: (D)

12. Which of the following technique(s) can be used to study conformational changes in myoglobin?

P. Mass spectrometry

Q. Fluorescence spectroscopy

R. Circular dichroism spectroscopy

S. Light microscopy

(A) P only

(B) P and S only

(C) Q and R only

(D) S only

Answer: (C)

13. Which one of the following bioreactor configurations is the basis for a trickling biological filter?

(A) Stirred tank

(B) Packed bed

(C) Air lift

(D) Fluidized bed

Answer: (B)

14. Cell type A secretes molecule X into the culture medium. Cell type B in the same culture responds to the molecule X by expressing protein Y. Which one of the following modes of signaling represents the interaction between A and B?

(A) Autocrine

(B) Juxtacrine

(C) Paracrine

(D) Intracrine

Answer: (C)

15. Which one of the following statements is true for actin?

(A) Actin filament is structurally polarized and the two ends are not identical

(B) De novo actin polymerization is a single-step process

(C) The pointed end of the actin filaments is the fast growing end

(D) Actin forms spindle fibers during mitosis

Answer: (A)

16. Standard error is

(A) the probability of a type I error in a statistical test

(B) the error in estimating a sample standard deviation

(C) the standard deviation of a variable that follows standard normal distribution

(D) the standard deviation of distribution of sample means

Answer: (D)

17. Which one of the following techniques is used to monitor RNA transcripts, both temporally and spatially?

(A) Northern blotting

(B) In situ hybridization

(C) Southern blotting

(D) Western blotting

Answer: (B)

18. Identify the character based method(s) used for the construction of a phylogenetic tree.

P. Maximum parsimony

Q. Neighbor joining

R. Maximum likelihood

S. Bootstrapping

(A) Q only

(B) P and R only

(C) Q and S only

(D) S only

Answer: (B)

19. Which one of the following is the solution for 𝑐𝑜𝑠2𝑥 + 2𝑐𝑜𝑠𝑥 + 1 = 0, for values of 𝑥 in the range of 0°<𝑥<360°?

(A) 45°

(B) 90°

(C) 180°

(D) 270°

Answer: (C)

20. Which one of the following plant secondary metabolites is a natural insecticide?

(A) Digitoxin

(B) Pyrethrin

(C) Salicylic acid

(D) Avenacin A-1

Answer: (B)

21. The determinant of the matrix is _________

Answer: (-10 to -10)

22. T he variable 𝑧 has a standard normal distribution. If 𝑃(0 ≤ 𝑧 ≤ 1) = 0.34, then 𝑃(𝑧2 > 1) is equal to (up to two decimal places) _________

Answer: (0.32 to 0.32)

23. T he absorbance of a solution of tryptophan measured at 280 nm in a cuvette of 2.0 cm path length is 0.56 at pH 7. The molar extinction coefficient (ε) for tryptophan at 280 nm is 5600 M-1cm-1 at pH 7. The concentration of tryptophan (in μM) in the solution is _________

Answer: (50 to 50)

24. A single stem cell undergoes 10 asymmetric cell divisions. The number of stem cells at the end is _________

Answer: (1 to 1)

25. G enomic DNA isolated from a bacterium was digested with a restriction enzyme that recognizes a 6-base pair (bp) sequence. Assuming random distribution of bases, the average length (in bp) of the fragments generated is _________

Answer: (4096 to 4096)

Q. 26 – Q. 55 carry two marks each.

26. In leguminous plants, both the rhizobium genes and the plant genes influence nodulation and nitrogen fixation. Which one of the following functions is NOT encoded by the host plant genes?

(A) Production of inducers that modify rhizobial cell wall

(B) Production of flavonoid inducers

(C) Establishment of contact between bacteria and legume

(D) Root hair curling

Answer: (D)

27. Which of the following cytokines are endogenous pyrogens?

P. Tumor necrosis factor-α

Q. Interleukin-1

R. Transforming growth factor-β

S. Interleukin-10

(A) P and Q only

(B) P and R only

(C) R and S only

(D) Q and S only

Answer: (A)

28. Match the classes of RNA molecules in Group I with their functions in Group II.

(A) P-3, Q-5, R-2, S-4

(B) P-1, Q-3, R-2, S-5

(C) P-1, Q-4, R-5, S-2

(D) P-4, Q-1, R-2, S-5

Answer: (D)

29. Determine the correctness or otherwise of the following Assertion [a] and the Reason [r]

Assertion: Ab initio gene finding algorithms that predict protein coding genes in eukaryotic genomes are not completely accurate.

Reason: Eukaryotic splice sites are difficult to predict.

(A) Both [a] and [r] are false

(B) [a] is true but [r] is false

(C) Both [a] and [r] are true and [r] is the correct reason for [a]

(D) Both [a] and [r] are true but [r] is not the correct reason for [a]

Answer: (C)

30. Which one of the following amino acids is catalyzed by activated macrophages to produce reactive nitrogen species?

(A) Arginine

(B) Asparagine

(C) Cysteine

(D) Histidine

Answer: (A)

31. Determine the correctness or otherwise of the following Assertion [a] and the Reason [r]

Assertion: The association constant in water for the G-C base pair is three times lower than that for the A-T base pair.

Reason: There are three hydrogen bonds in the G-C base pair and two in the A-T base pair.

(A) Both [a] and [r] are true and [r] is the correct reason for [a]

(B) [a] is false but [r] is true

(C) Both [a] and [r] are false

(D) Both [a] and [r] are true and [r] is not the correct reason for [a] 

Answer: (B)

32. Which one of the combinations of the following statements is true about antibody structure?

P. Limited proteolysis of rabbit IgG with the enzyme pepsin generates two antigen-binding regions (Fab) and an Fc fragment

Q. Limited proteolysis of rabbit IgG with the enzyme papain generates a single bivalent antigen-binding region F(ab′)2 and peptide fragments

R. The Fc fragment of IgG can self-associate and crystallize into a lattice S. The F(ab′)2 fragment of IgG is composed of both light and heavy chains

(A) P and Q only

(B) P and R only

(C) R and S only

(D) Q and S only

Answer: (C)

33. Which one of the following statements is true with regard to processing and presentation of protein antigens?

(A) In the class II MHC pathway, protein antigens in the cytosol are processed by proteasomes

(B) In the class I MHC pathway, extracellular protein antigens are endocytosed into vesicles and processed

(C) In the class I MHC pathway, transporter associated antigen processing (TAP) protein is required for translocating  rocessed peptides generated in the cytosol

(D) Invariant chain in endoplasmic reticulum is involved in transport of peptides and loading of class I MHC 

Answer: (C)

34. Which of the following are true about bacterial superoxide dismutase?

P. Present in obligate aerobes

Q. Present in facultative anaerobes

R. Present in aerotolerant anaerobes

S. Absent in obligate aerobes

(A) P and Q only

(B) P, Q and R only

(C) P and R only

(D) Q and S only

Answer: (B)

35. Which of the following are true with regard to anaerobic respiration in bacteria?

P. The final electron acceptor is an inorganic substance other than molecular oxygen

Q. The number of ATP molecules produced per glucose molecule is more than that produced in aerobic respiration

R. The number of ATP molecules produced per glucose molecule is less than that produced in aerobic respiration

S. Only substrate level phosphorylation is used to generate ATP

(A) P and S only

(B) Q and S only

(C) P and R only

(D) P, Q and S only

Answer: (C)

36. Shear stress versus shear rate behavior of four different types of fluids (I, II, III and IV) are shown in the figure below.

Which one of the following options is correct?

(A) I-Newtonian, II-Bingham plastic, III-Dilatant, IV-Pseudoplastic

(B) I-Pseudoplastic, II-Dilatant, III-Newtonian, IV-Bingham plastic

(C) I-Newtonian, II-Pseudoplastic, III-Bingham plastic, IV-Dilatant

(D) I-Newtonian, II-Bingham plastic, III-Pseudoplastic, IV-Dilatant

Answer: (D)

37. An analysis of DNA-protein interactions was carried out using all DNA-protein complexes in the protein data bank (PDB). The frequency distribution of four amino acid residues, represented as P, Q, R and S, occurring in non-covalent interactions between the protein and DNA backbone is shown below.

Which one of the following is correct?

(A) P-Lys, Q-Arg, R-Gln, S-Glu

(B) P-Gln, Q-Glu, R-Lys, S-Arg

(C) P-Asn, Q-Asp, R-Arg, S-Lys

(D) P-His, Q-Glu, R-Gln, S-Lys

Answer: (A)

38. A pedigree of an inheritable disease is shown below.

What type of inheritance does the disease follow?

(A) Autosomal dominant

(B) X-linked dominant

(C) X-linked recessive

(D) Autosomal recessive

Answer: (C)

39. Match the industrial products mentioned in Group I with their producer organisms in Group II

(A) P-4, Q-3, R-1, S-2

(B) P-3, Q-1, R-2, S-4

(C) P-2, Q-1, R-4, S-3

(D) P-3, Q-1, R-4, S-2

Answer: (D)

40. 5′ capping of mRNA transcripts in eukaryotes involves the following events:

P. Addition of GMP on the 5′ end

Q. Removal of γ-phosphate of the triphosphate on first base at the 5′ end

R. 5′-5′ linkage between GMP and the first base at 5′ end

S. Addition of methyl group to N7 position of guanine

Which one of the following is the correct sequence of events?

(A) P, Q, R, S

(B) P, R, Q, S

(C) Q, P, R, S

(D) Q, P, S, R

Answer: (C)

41. Calculate the following integral (up to two decimal places)

Answer: (5.30 to 5.34)

42. The probability distribution for a discrete random variable 𝑋 is given below.

The expectation value of 𝑋 is (up to one decimal place) _________

Answer: (2.1 to 2.1)

43. If 1+𝑟 + 𝑟2+ 𝑟3+⋯∞ = 1.5,

then, 1 + 2𝑟 + 3𝑟2 + 4𝑟3+⋯∞= (up to two decimal places) _________

Answer: (2.25 to 2.25)

44. Moist heat sterilization of spores at 121°C follows first order kinetics as per the expression:

where, N is the number of viable spores, t is the time, kd is the rate constant and is the rate of change of viable spores.

If kd value is 1.0 min-1, the time (in minutes) required to reduce the number of viable spores from an initial value of 1010 to a final value of 1 is (up to two decimal places) _________

Answer: (23.02 to 23.04)

45. An aqueous solution containing 6.8 mg/L of an antibiotic is extracted with amyl acetate. If the partition coefficient of the antibiotic is 170 and the ratio of water to solvent is 85, then the extraction factor is _________

Answer: (2 to 2)

46. A microbial strain is cultured in a 100 L stirred fermenter for secondary metabolite production. If the specific rate of oxygen uptake is 0.4 h-1 and the oxygen solubility in the broth is 8 mg/L, then the volumetric mass transfer coefficient (KLa) (in s-1) of oxygen required to achieve a maximum cell concentration of 12 g/L is (up to two decimal places) _________

Answer: (0.16 to 0.17)

47.  In a chemostat, the feed flow rate and culture volume are 100 ml/h and 1.0 L, respectively. With glucose as substrate, the values of μmax and Ks are 0.2 h-1 and 1 g/L, respectively. For a glucose concentration of 10 g/L in the feed, the effluent substrate concentration (in g/L) is _________

Answer: (1 to 1)

48. Mammalian cells in active growth phase were seeded at a density of 1×105 cells/ml. After 72 hours, 1×106 cells/ml were obtained. The population doubling time of the cells in hours is (up to two decimal places) _________

Answer: (21.00 to 22.00)

49. Y east converts glucose to ethanol and carbon dioxide by glycolysis as per the following reaction: 

C6H12O6 → 2C2H5OH + 2CO2

Assuming complete conversion, the amount of ethanol produced (in g) from 200 g of glucose is (up to two decimal places) _________

Answer: (102.00 to 103.00)

50. At the end of a batch culture, glucose solution is added at a flow rate of 200 ml/h. If the culture volume after 2 h of glucose addition is 1000 ml, the initial culture volume (in ml) is _________

Answer: (600 to 600)

51. Consider the following alignment of two DNA sequences:

Assuming an affine gap scoring scheme of an identity matrix for substitution, a gap initiation penalty of 1 and a gap extension penalty of 0.1, the score of the alignment is (up to one decimal place) _________

Answer: (1.8 to 1.9)

52. First order deactivation rate constants for soluble and immobilized amyloglucosidase enzyme are 0.03 min-1 and 0.005 min-1, respectively. The ratio of half-life of the immobilized enzyme to that of the soluble enzyme is (rounded off to the nearest integer) _________

Answer: (6 to 6)

53. Consider a simple uni-substrate enzyme that follows Michaelis-Menten kinetics. When the enzyme catalyzed reaction was carried out in the presence of 10 nM concentration of an inhibitor, there was no change in the maximal velocity. However, the slope of the Lineweaver-Burk plot increased 3-fold. The dissociation constant for the enzyme-inhibitor complex (in nM) is _________

Answer: (5 to 5)

54. The product of complete digestion of the plasmid shown below with EcoRI and HaeIII was purified and used as a template in a reaction containing Klenow fragment of DNA polymerase, dNTPs and [α-32P]-dATP in a suitable reaction buffer. The product thus obtained was purified and subjected to gel electrophoresis followed by autoradiography.

The number of bands that will appear on the X-ray film is _________

Answer: (2 to 2)

55. A rod shaped bacterium has a length of 2 μm, diameter of 1 μm and density the same as that of water. If proteins constitute 15% of the cell mass and the average protein has a mass of 50 kDa, the number of proteins in the cell is _________
(1 Da = 1.6 × 10-24g)

Answer: (2900000 to 3200000)

GATE Exam 2018 Architecture and Planning (AR) Question Paper With Answer Key

Architecture and Planning

General Aptitude (GA) Set-4

Q. 1 – Q. 5 carry one mark each.

1. “ When she fell down the _______, she received many _______ but little help.”

The words that best fill the blanks in the above sentence are

(A) stairs, stares

(B) stairs, stairs

(C) stares, stairs

(D) stares, stares

Answer: (A)

2.  “ In spite of being warned repeatedly, he failed to correct his _________ behaviour.”

The word that best fills the blank in the above sentence is

(A) rational

(B) reasonable

(C) errant

(D) good

Answer: (C)

3. For 0 ≤ 𝑥 ≤ 2𝜋, sin 𝑥 and cos 𝑥 are both decreasing functions in the interval ________.

(A) 

(B) 

(C) 

(D) 

Answer: (B)

4. The area of an equilateral triangle is √3. What is the perimeter of the triangle?

(A) 2

(B) 4

(C) 6

(D) 8

Answer: (C)

5. Arrange the following three-dimensional objects in the descending order of their volumes:

(i) A cuboid with dimensions 10 cm, 8 cm and 6 cm

(ii) A cube of side 8 cm

(iii) A cylinder with base radius 7 cm and height 7 cm

(iv) A sphere of radius 7 cm

(A) (i), (ii), (iii), (iv)

(B) (ii), (i), (iv), (iii)

(C) (iii), (ii), (i), (iv)

(D) (iv), (iii), (ii), (i)

Answer: (D)

Q. 6 – Q. 10 carry two marks each.

6. An automobile travels from city A to city B and returns to city A by the same route. The speed of the vehicle during the onward and return journeys were constant at 60 km/h and 90 km/h, respectively. What is the average speed in km/h for the entire journey?

(A) 72

(B) 73

(C) 74

(D) 75

Answer: (A)

7. A set of 4 parallel lines intersect with another set of 5 parallel lines. How many parallelograms are formed?

(A) 20

(B) 48

(C) 60

(D) 72

Answer: (C)

8. To pass a test, a candidate needs to answer at least 2 out of 3 questions correctly. A total of 6,30,000 candidates appeared for the test. Question A was correctly answered by 3,30,000 candidates. Question B was answered correctly by 2,50,000  candidates. Question C was answered correctly by 2,60,000 candidates. Both questions A and B were answered correctly by 1,00,000 candidates. Both questions B and C were answered correctly by 90,000 candidates. Both questions A and C were answered correctly by 80,000 candidates. If the number of students answering all questions correctly is the same as the number answering none, how many candidates failed to clear the test?

(A) 30,000

(B) 2,70,000

(C) 3,90,000

(D) 4,20,000

Answer: (D)

9. If 𝑥2 + 𝑥 − 1 = 0 what is the value of 

(A) 1

(B) 5

(C) 7

(D) 9

Answer: (C)

10. In a detailed study of annual crow births in India, it was found that there was relatively no growth during the period 2002 to 2004 and a sudden spike from 2004 to 2005. In another unrelated study, it was found that the revenue from cracker sales in India which remained fairly flat from 2002 to 2004, saw a sudden spike in 2005 before declining again in 2006. The solid line in the graph below refers to annual sale of crackers and the dashed line refers to the annual crow births in India. Choose the most appropriate inference from the above data.

(A) There is a strong correlation between crow birth and cracker sales.

(B) Cracker usage increases crow birth rate.

(C) If cracker sale declines, crow birth will decline.

(D) Increased birth rate of crows will cause an increase in the sale of crackers.

Answer: (A)

Architecture and Planning

1. In a Colour Wheel, Red and Blue colours are

(A) Tertiary

(B) Complementary

(C) Secondary

(D) Primary

Answer: (D)

2. In a bird’s eye perspective view of a cuboid, the maximum number of vanishing points is

(A) 1

(B) 2

(C) 3

(D) 6

Answer: (C)

3. The compressive strength of M-25 concrete is

(A) 25 kg/sqm

(B) 25 N/sqmm

(C) 250 N/sqmm

(D) 2.5 N/sqmm

Answer: (B)

4.In Critical Path Method (CPM) for time scheduling, ‘forward pass calculation’ is carried out for determining

(A) Late start and early finish time

(B) Early start and early finish time

(C) Late start and late finish time

(D) Early start and late finish time

Answer: (B)

5. Collapse of the World Trade Center (WTC), New York, in 2001, was due to

(A) Wind load failure

(B) Foundation failure

(C) Thermal performance failure of reinforcement steel in RCC

(D) Thermal performance failure of structural steel

Answer: (D)

6. During the construction of tall buildings, the equipment used for hoisting building materials to the upper floors is a

(A) Goods lift

(B) Capsule lift

(C) Gantry crane

(D) Tower crane

Answer: (D)

7. A Rock-cut style of architecture is represented by

(A) Shyama Rama Temple, Bishnupur

(B) Kailasa Temple, Ellora

(C) Kandariya Mahadeva Temple, Khajuraho

(D) Sanchi Stupa, Sanchi

Answer: (B)

8. ‘Area based development’ and ‘Pan city development’ are part of

(A) Smart City Mission

(B) Digital India Mission

(C) Swachh Bharat Mission

(D) Atal Innovation Mission

Answer: (A)

9. In mass transportation, LRTS stands for

(A) Light Rail Transit System

(B) Linear Rail Transit System

(C) Light Rail Transportation System

(D) Linear Rail Transportation System

Answer: (A)

10. The structural grid type shown in the figure below is a

(A) Tartan Grid

(B) Square Grid

(C) Rectangular Grid

(D) Irregular Grid

Answer: (A)

11. Assuming other variables remaining constant, the Tropical Summer Index

(A) Increases with increase in air velocity

(B) Decreases with increase in wet-bulb temperature

(C) Decreases with increase in globe temperature

(D) Increases with increase in vapour pressure

Answer: (D)

12. Government of India’s urban development program ‘HRIDAY’ stands for

(A) Heritage Rejuvenation Implementation Development Aayog Yojana

(B) Heritage Review Implementation Development Augmentation Yojana

(C) Heritage City Development and Augmentation Yojana

(D) Heritage City Improvement and Development Aawas Yojana

Answer: (C)

13. As per the Urban and Regional Development Plan Formulation and Implementation (URDPFI) guidelines, the plan period considered in a ‘Perspective plan’ is

(A) 1-10 years

(B) 11-15 years

(C) 20-30 years

(D) 35-45 years

Answer: (C)

14. The Hall of Nations, New Delhi, was designed by

(A) Charles Correa

(B) Raj Rewal

(C) Joseph Allen Stein

(D) A. P. Kanvinde

Answer: (B)

15. As per the National Building Code of India 2016, the minimum turning radius (in metres) required for fire tender movement is

(A) 8.0

(B) 8.5

(C) 9.0

(D) 9.5

Answer: (C)

16. Sidi Bashir Mosque with ‘Shaking Minarets’ is located in

(A) Ajmer

(B) Allahabad

(C) Ahmedabad

(D) Amritsar

Answer: (C)

17. ‘Sight Distance’ is considered in the design of

(A) Road intersection

(B) Fenestration

(C) Open kitchen

(D) Auditorium

Answer: (A)

18. In India, the term ‘Town Planning Scheme’ refers to

(A) Land renewal

(B) Land rejuvenation

(C) Land reclamation

(D) Land readjustment

Answer: (D)

19. Bamboo is a type of

(A) Shrub

(B) Timber

(C) Evergreen tree

(D) Perennial grass

Answer: (D)

20. According to the UN, one of the components for measuring ‘inclusive growth’ is

(A) Economic well-being

(B) Physical infrastructure

(C) Education

(D) Life expectancy

Answer: (A or B Or C)

21. The unit of measurement of Damp Proof Course (DPC) in building construction is

(A) kg

(B) cum

(C) sqm

(D) rm

Answer: (C)

22. Which of the following is NOT a Building Information Modeling software tool

(A) Adobe Illustrator

(B) Bentley Microstation

(C) Autodesk Revit

(D) Graphisoft ARCHICAD

Answer: (A)

23. The concentric circles in a solar chart represent

(A) Azimuth angle

(B) Altitude angle

(C) Horizontal shadow angle

(D) Vertical shadow angle

Answer: (B)

24. A room of 3m × 3m × 3m has a reverberation time of 0.8 sec. Using Sabine’s method, the total absorption in the room is _____________ sabin (up to one decimal place).

Answer: (5.3 to 5.7)

25. A 25 storeyed building has 5 lifts. The resulting waiting time is 35 sec and ‘Return Travel Time’ is 175 sec. The number of lifts required for reducing waiting time to 25 sec, without increasing the lift speed, is _______________

Answer: (7.0 to 7.0)

Q. 26 – Q. 55 carry two marks each.

26. Match the planning documents in Group-I with their respective government schemes in Group-II

(A) P-4, Q-1, R-5, S-2

(B) P-3, Q-5, R-4, S-2

(C) P-5, Q-1, R-4, S-3

(D) P-3, Q-5, R-4, S-1

Answer: (D)

27. Associate the fire safety requirements for high rise buildings in Group-I with corresponding standards of the National Building Code of India 2016 in Group-II

(A) P-4, Q-1, R-5, S-2

(B) P-3, Q-5, R-4, S-1

(C) P-3, Q-5, R-1, S-2

(D) P-4, Q-5, R-1, S-3

Answer: (C)

28. Match the photometric quantities in Group-I with their respective units in Group-II

(A) P-3, Q-2, R-5, S-4

(B) P-5, Q-4, R-2, S-1

(C) P-5, Q-1, R-2, S-3

(D) P-3, Q-1, R-2, S-4

Answer: (D)

29. Associate the symbols in Group I with their meanings in Group II

(A) P-5, Q-3, R-1, S-2

(B) P-1, Q-5, R-3, S-4

(C) P-1, Q-3, R-4, S-5

(D) P-5, Q-3, R-4, S-2

Answer: (D)

30. Match the elements in Group-I with the building components in Group-II

(A) P-5, Q-3, R-4, S-1

(B) P-2, Q-4, R-3, S-1

(C) P-2, Q-4, R-5, S-3

(D) P-5, Q-3, R-4, S-2

Answer: (D)

31. Match the iconic architectural examples in Group-I with their predominant structural systems in Group-II

(A) P-1, Q-3, R-5, S-4

(B) P-4, Q-1, R-2, S-3

(C) P-4, Q-5, R-2, S-1

(D) P-5, Q-4, R-3, S-2

Answer: (C)

32. Match the building materials in Group-I with their distinctive properties in Group-II

(A) P-5, Q-3, R-2, S-1

(B) P-5, Q-4, R-1, S-2

(C) P-1, Q-4, R-5, S-2

(D) P-4, Q-3, R-1, S-5

Answer: (B)

33. Match the built forms in Group-I with their descriptions in Group-II

(A) P-1, Q-4, R-3, S-2

(B) P-4, Q-3, R-1, S-5

(C) P-4, Q-3, R-5, S-2

(D) P-3, Q-1, R-5, S-2

Answer: (C)

34. Match the building configuration characteristics in Group-I with their seismic consequences in Group-II

(A) P-3, Q-1, R-2, S-4

(B) P-2, Q-3, R-1, S-5

(C) P-4, Q-3, R-1, S-5

(D) P-3, Q-5, R-2, S-1

Answer: (B)

35. Match the landscaping terms in Group-I with their descriptions in Group-II

(A) P-5, Q-3, R-1, S-4

(B) P-3, Q-5, R-1, S-4

(C) P-2, Q-3, R-1, S-5

(D) P-5, Q-2, R-4, S-1

Answer: (A)

36. Match the planning principles in Group-I with their descriptions in Group-II

(A) P-2, Q-1, R-4, S-3

(B) P-2, Q-1, R-5, S-3

(C) P-4, Q-2, R-5, S-3

(D) P-2, Q-3, R-5, S-4

Answer: (A)

37. Match the cities in Group-I with their planners in Group-II

(A) P-2, Q-4, R-1, S-3

(B) P-4, Q-1, R-5, S-2

(C) P-2, Q-1, R-5, S-3

(D) P-2, Q-3, R-4, S-5

Answer: (C)

38. Match the Temples in Group-I with their Dynastic period in Group-II

(A) P-4, Q-5, R-1, S-2

(B) P-5, Q-1, R-2, S-3

(C) P-2, Q-5, R-1, S-3

(D) P-4, Q-1, R-2, S-5

Answer: (A)

39. Match the Buildings in Group-I with their Architects in Group-II

(A) P-3, Q-4, R-2, S-5

(B) P-3, Q-4, R-1, S-2

(C) P-2, Q-4, R-1, S-5

(D) P-2, Q-5, R-4, S-3

Answer: (A)

40. Match the following urban conservation themes in Group-I with their respective descriptions in Group-II

(A) P-2, Q-5, R-4, S-3

(B) P-2, Q-1, R-4, S-5

(C) P-3, Q-2, R-1, S-4

(D) P-3, Q-1, R-3, S-5

Answer: (B)

41. A Single Phase Neutral (SPN) electrical circuit has a power consumption of 330W. Considering a voltage of 110V and power factor of 0.8, the electrical current drawn is ___________ Amp (up to one decimal place).

Answer: (3.7  to 3.8)

42. A building with 100 sqm roof area is connected to a 72 cum rainwater collection tank. If the rainfall is 60 mm per hour and the loss during water storage is 20%, then the time taken to fill the tank completely is_______ hours.

Answer: (15.0 to 15.0)

43. The planning norms for provision of schools in a given town is shown in the table below

Total land area required for providing all types of schools for a population of 200,000 is ___________ hectares.

Answer: (104 to 104)

44. In a mixed use development on a 2.0 hectare site with 2.0 FAR, the ratio of residential to commercial floor area is 3:2. The minimum parking (in ECS) needed per 100 sqm of residential and commercial floor area is 1.0 and 1.25 respectively. Considering full FAR utilization, the total parking requirement is ____________ ECS.

Answer: (440 to 440)

45. A plotted housing scheme on a site of 12 hectare has 60% saleable area. The average unit cost of land development is INR 300 million per hectare. If the profit margin is 20%, then the selling price of land per hectare is __________ million INR.

Answer: (600 to 600)

46. An isolated enclosure shown in the Figure has inlet P and outlet Q of 2 sqm each, on the opposite walls. The outdoor wind speed is 5 m/sec. If the coefficient of effectiveness is 0.6, the rate of natural ventilation in the enclosure due to wind action is _________ cum/hr.

Answer: (21600 to 21600)

47. A 5m × 5m × 3m room has four 230 mm thick external brick walls. Total wall fenestration is 10 sqm. The temperature difference between indoor and outdoor is 2 degC. The air to air transmittance values for 230 mm thick brick wall and 200 mm thick aerated concrete block wall are 2.4 and 1.7 W/sqm degC respectively. If the brick walls are replaced with the aerated concrete block walls, then the change in conductive heat flow through the walls is _________W.

Answer: (69.5 to 70.5)

48. For an activity, ‘optimistic time duration’ is 4 days, ‘pessimistic time duration’ is 11 days and ‘most-likely time duration’ is 8 days. The PERT value of time duration is______ days (up to one decimal place).

Answer: (7.8 to 7.9)

49. In the Figure, the negative bending moment at point A of the cantilever is ________ kNm.

Answer: (224 to 226)

50. The water consumption of a high rise apartment building with 60 dwelling units having an average household size of 5 persons is 135 lpcd. Assuming 80% of the total use is met with recycled water supply, the daily domestic demand for the building is _________ litres.

Answer: (8100 to 8100)

51. In India, for 1.0 cum of M-20 grade concrete, the number of cement bags required is ________ (up to two decimal places).

Answer: (5 to 9)

52. The sound power level of an outdoor non-directional point source is 90 dB. Considering an atmospheric impedance of 400 rayls, the sound pressure level at 10 m distance from the source is _______ dB.

Answer: (58 to 60)

53. The live load and dead load in a three storeyed residential building, transferred through a single column, is 12 tons and 18 tons respectively. If the soil bearing capacity is 10 ton/sqm and the factor of safety is 1.5, the area of column footing is _____________ sqm (up to one decimal place).

Answer: (4.0 to 5.0)

54. The indoor illumination requirement for a building is 350 Lux. If the daylight factor is 2.7 and the design sky illuminance is 9000 Lux, then the required supplementary artificial lighting is ____________ Lux.

Answer: (107 to 107)

55. Two design options of a business building on a 10.0 hectare site are being compared for built up area. Floor to floor height of Option A is 3.6 m and that of Option B is 4.5 m. If the maximum allowable building height is 45 m with same ground coverage for both options, the additional built up area achievable in Option A over Option B is______percent.

Answer: (20 to 20)

GATE Exam 2018 Agricultural Engineering (AG) Question Paper With Answer Key

Agricultural Engineering

General Aptitude (GA) Set-4

Q. 1 – Q. 5 carry one mark each.

1. “ When she fell down the _______, she received many _______ but little help.”

The words that best fill the blanks in the above sentence are

(A) stairs, stares

(B) stairs, stairs

(C) stares, stairs

(D) stares, stares

Answer: (A)

2.  “ In spite of being warned repeatedly, he failed to correct his _________ behaviour.”

The word that best fills the blank in the above sentence is

(A) rational

(B) reasonable

(C) errant

(D) good

Answer: (C)

3. For 0 ≤ 𝑥 ≤ 2𝜋, sin 𝑥 and cos 𝑥 are both decreasing functions in the interval ________.

(A) 

(B) 

(C) 

(D) 

Answer: (B)

4. The area of an equilateral triangle is √3. What is the perimeter of the triangle?

(A) 2

(B) 4

(C) 6

(D) 8

Answer: (C)

5. Arrange the following three-dimensional objects in the descending order of their volumes:

(i) A cuboid with dimensions 10 cm, 8 cm and 6 cm

(ii) A cube of side 8 cm

(iii) A cylinder with base radius 7 cm and height 7 cm

(iv) A sphere of radius 7 cm

(A) (i), (ii), (iii), (iv)

(B) (ii), (i), (iv), (iii)

(C) (iii), (ii), (i), (iv)

(D) (iv), (iii), (ii), (i)

Answer: (D)

Q. 6 – Q. 10 carry two marks each.

6. An automobile travels from city A to city B and returns to city A by the same route. The speed of the vehicle during the onward and return journeys were constant at 60 km/h and 90 km/h, respectively. What is the average speed in km/h for the entire journey?

(A) 72

(B) 73

(C) 74

(D) 75

Answer: (A)

7. A set of 4 parallel lines intersect with another set of 5 parallel lines. How many parallelograms are formed?

(A) 20

(B) 48

(C) 60

(D) 72

Answer: (C)

8. To pass a test, a candidate needs to answer at least 2 out of 3 questions correctly. A total of 6,30,000 candidates appeared for the test. Question A was correctly answered by 3,30,000 candidates. Question B was answered correctly by 2,50,000  candidates. Question C was answered correctly by 2,60,000 candidates. Both questions A and B were answered correctly by 1,00,000 candidates. Both questions B and C were answered correctly by 90,000 candidates. Both questions A and C were answered correctly by 80,000 candidates. If the number of students answering all questions correctly is the same as the number answering none, how many candidates failed to clear the test?

(A) 30,000

(B) 2,70,000

(C) 3,90,000

(D) 4,20,000

Answer: (D)

9. If 𝑥2 + 𝑥 − 1 = 0 what is the value of 

(A) 1

(B) 5

(C) 7

(D) 9

Answer: (C)

10. In a detailed study of annual crow births in India, it was found that there was relatively no growth during the period 2002 to 2004 and a sudden spike from 2004 to 2005. In another unrelated study, it was found that the revenue from cracker sales in India which remained fairly flat from 2002 to 2004, saw a sudden spike in 2005 before declining again in 2006. The solid line in the graph below refers to annual sale of crackers and the dashed line refers to the annual crow births in India. Choose the most appropriate inference from the above data.

(A) There is a strong correlation between crow birth and cracker sales.

(B) Cracker usage increases crow birth rate.

(C) If cracker sale declines, crow birth will decline.

(D) Increased birth rate of crows will cause an increase in the sale of crackers.

Answer: (A)

Agricultural Engineering

1. The general solution to the second order linear homogeneous differential equation y″ – 6y′ + 25y = 0 is

(A) e3x(a cos 4x + b sin 4x)

(B) e3ix(a cos 4x + b sin 4x)

(C) e4x(a cos 3x + b sin 3x)

(D) e4ix(a cos 3x + b sin 3x)

Answer: (A)

2. Solution of f(x) = x4 +2 x3 – 4 x2 + 3 x – 1 = 0 is

(A) 0.333

(B) 0.646

(C) 0.658

(D) 1.000

Answer: (C)

3. Integration of is

(A) 

(B) 

(C) 

(D) 

Answer: (D)

4. The type of the sequence  is

(A) oscillatory

(B) bounded

(C) converging

(D) diverging

Answer: (C)

5. For accepting or rejecting a null hypothesis, which one of the following is NOT used as a significance test method in statistics?

(A) Z-test

(B) Student’s t-test

(C) Pearson’s correlation

(D) Relative standard deviation

Answer: (D)

6. For a two-wheel drive tractor, use of differential lock in adverse field condition ensures

(A) equal distribution of torque to both the drive wheels.

(B) equal distribution of power to both the drive wheels.

(C) distribution of higher amount of torque to the wheel under poor traction.

(D) distribution of higher amount of torque to the wheel under better traction.

Answer: (D)

7. During field evaluation of a combine harvester, total grain collected at the grain tank was 135 kg. Amount of threshed grain found over walker and shoe were 0.65 kg and 2.4 kg, respectively. Unthreshed grain lost with straw and chaff were 4.54 kg and 0.28 kg, respectively. Threshing efficiency of the combine harvester in percent is

(A) 94.37

(B) 94.49

(C) 96.50

(D) 96.63

Answer: (D)

8. Match the following items of Column I with the corresponding items of Column II:

(A) P-2, Q-3, R-1, S-4

(B) P-4, Q-1, R-2, S-3

(C) P-4, Q-3, R-2, S-1

(D) P-2, Q-4, R-1, S-3

Answer: (B)

9. Constituents of the producer gas contributing to its heating value are

(A) CO and CO2

(B) CH4 and CO2

(C) CO and H2

(D) CO2 and H2

Answer: (C)

10. One of the key assumptions made by Dupuit-Forchheimer about the flow behavior in the porous medium towards subsurface drains is

(A) homogeneous medium

(B) isotropic medium

(C) horizontal streamlines

(D) uniform recharge

Answer: (C)

11. The depths from the soil surface to subsurface tile drains, impermeable soil layer and the highest water table are measured as 2.8 m, 5.0 m and 0.8 m, respectively. The effective hydraulic head for drainage in meter is

(A) 0.8

(B) 2.0

(C) 2.2

(D) 4.2

Answer: (B)

12. The discharge from a sprinkler nozzle depends on

(A) operating pressure and nozzle geometry.

(B) operating pressure and distribution pattern.

(C) application rate and nozzle angle.

(D) operating pressure and application rate.

Answer: (A)

13. If the void ratio of a soil column is 0.43, the soil porosity is

(A) 0.30

(B) 0.40

(C) 0.70

(D) 0.75

Answer: (A)

14. Which one of the following is a WRONG statement?

(A) The head generated by a centrifugal pump at zero discharge is the ‘shutoff head’.

(B) To avoid cavitation in centrifugal pumps, the net positive suction head should be more than the theoretical atmospheric pressure.

(C) According to the affinity laws of centrifugal pumps, the head varies with the square of the impeller speed.

(D) Most of the turbine pumps have operational characteristics closer to those of the centrifugal pumps than the propeller pumps.

Answer: (B)

15. If the departure and latitude of a line during Theodolite survey are 70.03 m and -100 m, respectively, the whole circle bearing of this line in degree is

(A) 55

(B) 125

(C) 135

(D) 145

Answer: (D)

16. Convective film heat transfer coefficient (h) of air (thermal conductivity=0.025 W m-1 K-1) in W m-2 K-1, trapped between two parallel glass panes in a window 1.5 mm apart, is 

(A) 3.75

(B) 16.67

(C) 37.52

(D) 60.21

Answer: (B)

17. Log mean temperature difference (LMTD) correction factor (F) is applicable to

(A) Spiral tube heat exchanger

(B) Steam jacketed kettle

(C) Plate heat exchanger

(D) Evaporator tubes

Answer: (C)

18. Which one of the following statements related to parboiling of paddy is NOT correct?

(A) Irreversible granule swelling occurs during heating.

(B) Parboiling process is used to salvage wet or damaged paddy.

(C) Parboiled rice takes less time to cook as compared to raw rice due to starch gelatinization.

(D) Milling yield of paddy increases due to starch gelatinization.

Answer: (C)

19. In refining of the rice bran oil for edible purpose, neutralization process is carried out mainly to remove

(A) wax and organic impurities

(B) gums and mucilage

(C) saturated glycerides

(D) free fatty acids

Answer: (D)

20. Which one of the following chemicals is NOT used for fumigation in either horizontal or vertical storage structures to kill insects?

(A) Methyl bromide

(B) Phosphine

(C) Phostoxin

(D) Silver sulphate

Answer: (D)

21. Match the following agricultural/food by-products in Column I with their respective value added products in Column II.

(A) P-2, Q-3, R-1, S-4

(B) P-3, Q-4, R-2, S-1

(C) P-4, Q-3, R-2, S-1

(D) P-3, Q-1, R-2, S-4

Answer: (B)

22. An epicyclic gear train consists of a sun gear, four planet gears pinned on a planet carrier (which is mounted on the sun gear) and a fixed ring gear (in which the entire sun-planet gear assembly is inserted). If the ring gear has 56 teeth and each planet gear has 18 teeth, the number of teeth on the sun gear is _______.

Answer: (20.00 to 20.00)

23. A self-propelled power reaper with a 1.2 m wide cutter bar was operated at a forward speed of 4 km h-1. Turning loss during operation was observed to be 25 minutes per hectare. Neglecting any other losses, the field efficiency of the reaper will be ________%.

Answer: (83.00 to 84.00)

24. T he porosity and compressibility of a 7.8 m thick confined aquifer are 0.25 and 1×10-8 m2 N-1, respectively. The storage coefficient of the aquifer is 6.5×10-4. To release 650 m3 of water from 1 km2 of this aquifer, the average decline in hydraulic head will be ________m.

Answer: (1.00 to 1.00)

25. Molecular diffusivity (DAB) of water vapour in air is 2.6×10-5 m2 s-1 over an effective distance of 3 mm. Density and coefficient of viscosity of air are 1.2 kg m-3 and 2×10-5 kg m-1 s-1, respectively. Sherwood Number (NSh) for water vapour in air is _________.

Answer: (1.00 to 1.00)

Q. 26 – Q. 55 carry two marks each.

26. Rank of a matrix  is

(A) 1

(B) 2

(C) 3

(D) 4

Answer: (C)

27. A particle is subjected to forces P = 2 i – 5 j + 6 k and Q = – i + 2 j – k. The positional vectors are Work done by the resultant force (F = P + Q) to move the particle from A to B is

(A) 2

(B) -5

(C) 12

(D) -15

Answer: (D)

28. A two-wheel drive tractor weighing 18 kN has a wheel base 1.8 m. Its centre of gravity is located 600 mm ahead of the rear axle centre, under static condition, on a level ground. When this tractor is used to pull a disc plough hitched at a height of 390 mm from the ground, the draft observed is 6 kN. The change in reaction on rear wheels of the tractor due to pull in kN is

(A) 1.30

(B) 1.95

(C) 3.90

(D) 5.85

Answer: (A)

29. Match the following items in Column I with the corresponding items in Column II:

(A) P-4, Q-2, R-5, S-3, T-1

(B) P-4, Q-3, R-1, S-5, T-2

(C) P-3, Q-1, R-5, S-4, T-2

(D) P-3, Q-1, R-2, S-4, T-5

Answer: (C)

30. T he velocity (v) of a tractor, which starts from rest, is given at fixed intervals of time (t) as follows:

Using Simpson’s 1/3rd rule, the distance covered by the tractor in 20 minutes will be _________m.

Answer: (25.80 to 25.90)

31. In a box, there are 2 red, 3 black and 4 blue coloured balls. The probability of drawing 2 blue balls in sequence without replacing, and then drawing 1 black ball from this box is _________%.

Answer: (6.80 to 7.20)

32. An open belt drive system transmits 5 kW power using a flat belt of width and thickness as 80 mm and 5 mm, respectively. The driving shaft speed is 1500 rpm and the driven shaft speed is 500 rpm. The coefficient of friction between the belt and pulley is 0.20, and the wrap angle of the belt is 168°. If diameter of the smaller pulley is 200 mm, maximum stress induced in the belt will be _________ MPa.

Answer: (1.70 to 1.80)

33. A 2m3 biogas plant is to be operated using cow-dung as feedstock. The cow-dung is mixed with water in proportion of 1:1 (by weight) to form a slurry of density 1090 kg m-3. The yield of biogas is 0.036 m3 kg-1 of cow-dung. If the hydraulic retention time is 40 days, volume of the digester of the biogas plant will be ________ m3.

Answer: (3.90 to 4.20)

34. A power tiller with diesel engine produces 12 kW of brake power with a brake thermal efficiency of 30%. If the air-fuel ratio in the combustion process is 14:1 and heating value of the fuel is 45 MJ kg-1, air consumption rate of the engine will be ________ kg h-1.

Answer: (44.50 to 45.00)

35. Air enters into an engine cylinder at a pressure of 100 kPa and temperature of 300 K in the suction stroke of an ideal Otto cycle. The cylinder clearance volume is 600 cm3 and compression ratio is 8:1. The expansion stroke of the cycle is polytropic in nature. The pressure at the beginning of the expansion stroke is 10 MPa and the temperature at the end of the expansion stroke is 1800 K. The polytropic exponent of the expansion stroke is ________.

Answer: (1.30 to 1.39)

36. A tractor drawn five-tine sweep type cultivator is set at an angle (load angle) of 45° with the soil surface during its operation. The sweep of each tine experiences a normal force of 960 N on its surface. If the coefficient of soil-metal friction is 0.3, the total draft requirement of the cultivator is ________ kN.

Answer: (4.35 to 4.45)

37. A two-wheel drive tractor with rear wheel rolling radius of 600 mm develops a tractive force of 18.5 kN at a wheel slip of 12%. The engine speed is 2400 rpm and the transmission ratio from the engine to the rear wheels is 120:1. If the tractor experiences a motion resistance of 1.75 kN, the drawbar power developed by the tractor will be ________ kW.

Answer: (18.00 to 21.00)

38. A single plate dry clutch transmits 15 kW power at 1200 rpm. The clutch sustains a maximum axial load of 2.65 kN. The ratio of outer to inner diameter of the frictional surface is 1.25:1. Considering uniform wear with a coefficient of friction of 0.3 on both the frictional surfaces, the outer diameter of the clutch plate is ________ mm.

Answer: (166.00 to 168.00)

39. A precision seed planter can plant 10 seeds per revolution of the metering plate with a row to row distance of 450 mm at a speed of 6 km h-1. A plant population of 36 plants per square meter is desired for the crop. The germination percentage of the seed is 90%. If the planter ground wheel has a rolling radius of 350 mm, the speed ratio of metering plate to the ground wheel required to obtain the desired plant population is ________.

Answer: (3.90 to 4.10)

40. The elevations of pressure gauge and porous cup of the tensiometer installed in unsaturated zone are 145.8 m and 144.2 m, respectively. Pressure measured at the gauge is -19.62×103 N m-2. The specific weight of water is 9810 N m-3. The estimated pressure at the porous cup is ________ N m-2.

Answer: (-3924 to -3924)

41. The drawdown at the well face of a 30 cm diameter fully penetrating well in a confined aquifer is 3 m. The radius of influence of this well is 3 km. For the same discharge and aquifer condition, the drawdown at 300 m away from the centre of the well is ______m.

Answer: (0.68 to 0.71)

42. A permanent matured orchard has a tree spacing of 4 m×5 m. Each tree has a shading area of 40% to be irrigated with the ‘pig tail’ pattern multi-exit drip emitters. The effective wetting geometry of each emitter is 2 m×2 m. The emitters have discharge constant and exponent of 0.3 and 0.6, respectively. The coefficient of variation of emitter discharge is 0.06. The average and minimum operating pressures are 120 kPa and 100 kPa, respectively. The emission uniformity of the emitters is ________%.

Answer: (83 to 86)

43. The 6-hour unit hydrograph of a watershed is represented by an isosceles triangle with the peak of 180 m3 s-1 and time to peak of 18 hours. The phi-index (∅) of this watershed is 3.0 mm h-1 and the constant baseflow is 20 m3 s-1. The accumulated rainfall received in this watershed at 6 h and 12 h from the start of the storm are 38 mm and 106 mm, respectively. The resulting peak of the flood hydrograph due to this storm event is _______ m3 s-1.

Answer: (1280 to 1280)

44. Three geometrically identical Lysimeters (A, B and C) installed in a paddy field have uniform initial ponding depths of 12 cm. After a week, the recorded water depths in A, Band C are 10.4 cm, 8.6 cm, and 7.0 cm, respectively. Rainfall received during this week is 15 mm, and the crop coefficient of paddy is 0.94. Lysimeter ‘A’ has a closed bottom with no plant. Lysimeter ‘B’ has an open bottom with no plant. Lysimeter ‘C’ has an open bottom with paddy plants. Neglecting the boundary effects and groundwater contribution in the Lysimeters, the weekly potential evapotranspiration will be _______ cm.

Answer: (5.00 to 5.00)

45. A rectangular chute spillway is designed for gully erosion control with a drop (H) of 5 m, peak flow of 1.81 m3 s-1 and maximum inlet water level of 0.81 m. Frictional head loss over the apron is 20% of H. The design height of chute blocks is equal to the depth of flow in the water way. Acceleration due to gravity (g) is 9.81 m s-2. If coefficient of discharge of the weir section is 1.66, height of the chute blocks is _______m.

Answer: (0.13 to 0.14)

46. Furrows of 120 m length with 0.5% slope are made at 90 cm spacing. The maximum nonerosive stream flow rate is applied in a furrow that takes 1.0 hour to reach the lower end. Then this flow rate is reduced to half of its size and, subsequently, continued for another 1.0 hour. The average depth of applied water is ________ cm.

Answer: (6.00 to 6.00)

47. A cylindrical tank of 1.5 m diameter and 4 m height is filled with a liquid by a pipe of 2.5 cm internal diameter. The density and dynamic viscosity of the liquid are 1050 kg m-3 and 1.6×10-3 N s m-2, respectively. If flow in the pipe is turbulent, the maximum time required to fill the tank is _______ hours.

Answer: (16.30 to 16.50)

48. In a falling film evaporator, the inside and outside diameters of the tube wall are 25 mm and 27 mm, respectively. The tube is made of SS304 (thermal conductivity=15 W m-1 K-1) and the inside convective film coefficient is 750 W m-2 K-1. Outside the tube wall, film coefficient of condensing steam is 7175 W m-2 K-1. Based on the inside area of the tube, the overall heat transfer coefficient is __________ W m-2 K-1.

Answer: (650 to 670)

49. Mass flow rate of outside air through a duct is 735 kg h-1. Absolute humidity of air is 0.025 kg water vapour per kg dry air at 40°C. This air is mixed with equal quantity of moist exhaust air coming out of a counter current dryer at 55°C. The mixed air is heated up to 75°C to dry barley, fed at 174 kg h-1 , at an initial moisture content of 31% (wet basis) to a final value of 7% (dry basis). The absolute humidity of the exhaust air from the dryer in ‘kg water vapour per kg dry air’ will be ________.

Answer: (0.086  to 0.089)

50. One ton of marine fishery products are to be brought down from 32°C temperature to -18°C in half an hour time using a plate freezer. The freezing point of 85% water (based on total mass of the product) present in the fish is -0.3°C. Specific heat capacities of fresh and frozen fish solids (15% of total mass) are 3.2 and 1.8 kJ kg-1 K-1, respectively. Specific heat capacity of fresh water is 4.2 kJ kg-1 K-1 and that of ice is 2.2 kJ kg-1 K-1. Latent heat of crystallization of water is 335 kJ kg-1. For freezing the products, the compressor power consumption with a vapour compression refrigeration cycle (coefficient of performance, 3.66) is_________ kW.

Answer: (68.00 to 69.00)

51. Mycobacterium tuberculosis is having decimal reduction time of 13.5 s at 72°C. The count of the organism is to be reduced by eight logarithmic cycles in milk pasteurization with adequate holding at a temperature of 85°C. If Q10 value for the organism is 7.5, the minimum holding time for the desired sterility of this particular organism at 85°C is_________ seconds.

Answer: (7.80 to 8.00)

52. A horizontal screw conveyor of length 3.2 m conveys solid grain having bulk density of 725 kg m-3. The screw diameter, shaft diameter and pitch of the screw are 0.6 m, 0.24 m and 0.48 m, respectively. If the screw is operating with 80% of its volumetric capacity at a speed of 50 rpm, the actual discharge of the screw is_________ ton h-1.

Answer: (196.00 to 200.00)

53. In a feed milling plant, it has been observed that 80% of the feed passes through IS sieve 340 (3.25 mm opening) and 80% of the ground feed passes through IS sieve 40 (0.42 mm opening). The power requirement to crush the material with a feed rate of 3 ton h-1 is 6 kW. Power requirement to crush 2 ton h-1 of the same feed using the above system so that 80% of the ground feed pass through IS sieve 15 (opening 0.157 mm) is _________kW.

Answer: (7.90 to 8.10)

54. Solid food particles having nominal size of 0.2 mm with shape factor of 0.8 and density of 1040 kg m-3 are to be fluidized using air at 28°C. The density and pressure of air at the above-mentioned condition are 1.175 kg m-3 and 1.013×105 Pa, respectively. The voidage at minimum fluidizing condition is 0.48. Use the value of ‘g’ as 9.81 m s-2. If cross section of the empty bed is 0.5 m² and contains 520 kg of solids, the pressure drop at minimum fluidization condition is _______ kPa.

Answer: (9.80 to 10.40)

55. A single strength fruit juice is concentrated from 6% total solids (TS) to 24% by ultrafiltration. The feed stream has a flow rate of 12 kg min-1. The ultrafiltration membrane tube has an inside diameter of 80 mm and the pressure difference applied across the membrane is 2 MPa. If the permeability constant is 4×10-5 kg water m-² kPa-1 s-1, the length of the membrane tube is _________m.

Answer: (7.0 to 7.6)

GATE Exam 2018 Aerospace Engineering (AE) Question Paper With Answer Key

Aerospace Engineering

General Aptitude (GA) Set-2

Q. 1 – Q. 5 carry one mark each.

1. “The dress _________ her so well that they all immediately _________ her on her appearance.”

The words that best fill the blanks in the above sentence are

(A) complemented, complemented

(B) complimented, complemented

(C) complimented, complimented

(D) complemented, complimented

Answer: (D)

2. “The judge’s standing in the legal community, though shaken by false allegations of wrongdoing, remained _________.”
The word that best fills the blank in the above sentence is

(A) undiminished

(B) damaged

(C) illegal

(D) uncertain

Answer: (A)

3. Find the missing group of letters in the following series:

BC, FGH, LMNO, _____

(A) UVWXY

(B) TUVWX

(C) STUVW

(D) RSTUV

Answer: (B)

4. The perimeters of a circle, a square and an equilateral triangle are equal. Which one of the following statements is true?

(A) The circle has the largest area.

(B) The square has the largest area.

(C) The equilateral triangle has the largest area.

(D) All the three shapes have the same area.

Answer: (A)

5. The value of the expression is _______.

(A) -1

(B) 0

(C) 1

(D) 3

Answer: (C)

Q. 6 – Q. 10 carry two marks each.

6. Forty students watched films A, B and C over a week. Each student watched either only one film or all three. Thirteen students watched film A, sixteen students watched film B and nineteen students watched film C. How many students watched all three films?

(A) 0

(B) 2

(C) 4

(D) 8

Answer: (C)

7. A wire would enclose an area of 1936 m2, if it is bent into a square. The wire is cut into two pieces. The longer piece is thrice as long as the shorter piece. The long and the short pieces are bent into a square and a circle, respectively. Which of the following choices is closest to the sum of the areas enclosed by the two pieces in square meters?

(A) 1096

(B) 1111

(C) 1243

(D) 2486

Answer: (C)

8. A contract is to be completed in 52 days and 125 identical robots were employed, each operational for 7 hours a day. After 39 days, five-seventh of the work was completed. How many additional robots would be required to complete the work on time, if each robot is now operational for 8 hours a day?

(A) 50

(B) 89

(C) 146

(D) 175

Answer: (Marks to All)

9. A house has a number which needs to be identified. The following three statements are given that can help in identifying the house number.

i. If the house number is a multiple of 3, then it is a number from 50 to 59.

ii. If the house number is NOT a multiple of 4, then it is a number from 60 to 69.

iii. If the house number is NOT a multiple of 6, then it is a number from 70 to 79.

What is the house number?

(A) 54

(B) 65

(C) 66

(D) 76

Answer: (D)

10. An unbiased coin is tossed six times in a row and four different such trials are conducted. One trial implies six tosses of the coin. If H stands for head and T stands for tail, the following are the observations from the four trials:

(1) HTHTHT (2) TTHHHT (3) HTTHHT (4) HHHT__ __.

Which statement describing the last two coin tosses of the fourth trial has the highest probability of being correct?

(A) Two T will occur.

(B) One H and one T will occur.

(C) Two H will occur.

(D) One H will be followed by one T.

Answer: (B)

Aerospace Engineering

Q. 1 – Q. 25 carry one mark each.

1. Let  be two distinct vectors that are not parallel. The vector is

(A) zero.

(B) orthogonal to  alone.

(C) orthogonal to 

(D) orthogonal to  alone.

Answer: (D)

2. Consider the function  All the roots of this function

(A) form a finite set of points.

(B) lie on an elliptical curve.

(C) lie on the surface of a sphere.

(D) lie on a hyperbolic curve.

Answer: (B)

3. Consider a vector field given by This vector field is

(A) divergence-free and curl-free.

(B) curl-free but not divergence-free.

(C) divergence-free but not curl-free.

(D) neither divergence-free nor curl-free.

Answer: (B)

4. A jet aircraft is initially flying steady and level at its maximum endurance condition. For the aircraft to fly steady and level, but faster at the same altitude, the pilot should

(A) increase thrust alone.

(B) increase thrust and increase angle of attack.

(C) increase thrust and reduce angle of attack.

(D) reduce angle of attack alone.

Answer: (C)

5. The pilot of a conventional airplane that is flying steady and level at some altitude, deflects the port side aileron up and the starboard aileron down. The aircraft will then

(A) pitch, nose up.

(B) roll with the starboard wing up.

(C) pitch, nose down.

(D) roll with the port wing up.

Answer: (B)

6. A NACA 0012 airfoil has a trailing edge flap. The airfoil is operating at an angle of attack of 5 degrees with un-deflected flap. If the flap is now deflected by 5 degrees downwards, the CL versus α curve

(A) shifts right and slope increases.

(B) shifts left and slope increases.

(C) shifts left and slope stays the same.

(D) shifts right and slope stays the same.

Answer: (C)

7. An airplane requires a longer ground roll to lift-off on hot summer days because

(A) the thrust is directly proportional to free-stream density.

(B) the thrust is directly proportional to weight of the aircraft.

(C) the lift-off distance is directly proportional to free-stream density.

(D) the runway friction is high on hot summer days.

Answer: (A)

8. The velocity profile in an incompressible, laminar boundary layer is shown in the figure below. U is the free-stream velocity, u(y) is the stream-wise velocity component. The area of the black shaded region in the figure below represents the

(A) boundary layer thickness.

(B) momentum thickness.

(C) displacement thickness.

(D) shape factor.

Answer: (C)

9. The tangential velocity component ‘V’ of a spacecraft, which is in a circular orbit of radius ‘R’ around a spherical Earth (μ = GM → gravitational parameter of Earth) is given by the following expression.

(A) 

(B) 

(C) 

(D) 

Answer: (B)

10. Equation of the trajectory of a typical space object around any planet, in polar coordinates (r, θ) (i.e. a general conic section geometry), is given as follows. (h is angular momentum, μ is gravitational parameter, e is eccentricity, r is radial distance from the planet center, θ, is angle between vectors 

(A) 

(B) 

(C) 

(D) 

Answer: (C)

11. In an elliptic orbit around any planet, the location at which a spacecraft has the maximum angular velocity is

(A) apoapsis.

(B) periapsis.

(C) a point at +45° from periapsis.

(D) a point at –90° from apoapsis.

Answer: (B)

12. The pitching moment of a positively cambered NACA airfoil about its leading edge at zero-lift angle of attack is

(A) negative.

(B) positive.

(C) indeterminate.

(D) zero.

Answer: (A)

13. In a low-speed wind tunnel, the angular location(s) from the front stagnation point on a circular cylinder where the static pressure equals the free-stream static pressure, is

(A) ± 38°

(B) ± 30°

(C) ± 60°

(D) 0°

Answer: (B)

14. A thermocouple, mounted flush in an insulated flat surface in a supersonic laminar flow of air measures the

(A) static temperature.

(B) temperature greater than static but less than total temperature.

(C) total temperature.

(D) temperature greater than total temperature.

Answer: (B)

15. A shock wave is moving into still air in a shock tube. Which one of the following happens to the air?

(A) static temperature increases, total temperature remains constant.

(B) static temperature increases, total temperature increases.

(C) static temperature increases, total temperature decreases.

(D) static pressure increases, total temperature remains constant.

Answer: (B)

16. The highest limit load factor experienced by a civil transport aircraft is in the range

(A) 0.0 – 2.0

(B) 2.0 – 5.0

(C) 5.0 – 8.0

(D) 8.0 – 10.0

Answer: (B)

17. Determine the correctness or otherwise of the following statements, [a] and [r]:

[a] A closed-section box beam configuration is used in aircraft wings.

[r] Closed-section box beam configuration is capable of resisting torsional loads.

(A) Both [a] and [r] are true and [r] is the correct reason for [a].

(B) Both [a] and [r] are true but [r] is not the correct reason for [a].

(C) Both [a] and [r] are false.

(D) [a] is true but [r] is false.

Answer: (A)

18. The first law of thermodynamics is also known as conservation of

(A) mass.

(B) momentum.

(C) energy.

(D) species.

Answer: (C)

19. In an ideal gas turbine cycle, the expansion in a turbine is represented by

(A) an isenthalpic process.

(B) an isentropic process.

(C) an isobaric process.

(D) an isochoric process.

Answer: (B)

20. The determinant of the matrix is ______ (accurate to one decimal place).

Answer: (0.0 to 0.0)

21. The theoretical maximum velocity (in m/s) of air expanding from a reservoir at 700 K is __________ (accurate to two decimal places). Specific heat of air at constant pressure is 1005 J/(kg-K).

Answer: (1185.00 to 1186.50)

22. For a damped single degree of freedom system with damping ratio of 0.1, ratio of two successive peak amplitudes of free vibration is ___________ (accurate to two decimal places).

Answer: (1.75 to 1.95)

23. The natural frequency (in rad/s) of the spring-mass system shown in the figure below is _____ (accurate to one decimal place).

Answer: (2.0 to 2.0)

24. The stagnation pressures at the inlet and exit of a subsonic intake are 100 kPa and 98 kPa, respectively. The pressure recovery of this intake will be ______ (accurate to two decimal places).

Answer: (0.98 to 0.98)

25. A combustor is operating with a fuel-air ratio of 0.03. If the stoichiometric fuel-air ratio of the fuel used is 0.06, the equivalence ratio of the combustor will be _______ (accurate to two decimal places).

Answer: (0.50 to 0.50)

Q. 26 – Q. 55 carry two marks each.

26. The solution of the differential equation given that 𝑦=0 and at 𝑥=0 is

(A) 

(B) 

(C) 

(D) 

Answer: (B)

27. The relation between pressure (p) and velocity (V) for a steady, isentropic flow at two points along a streamline is, (c is a constant)

Answer: (C)

28. A thin airfoil is mounted in a low-speed, subsonic wind tunnel, in which the Mach number is 0.1. At a point on the airfoil, the pressure coefficient is measured to be –1.2. If the flow velocity is increased such that the free-stream Mach number is 0.6, the pressure coefficient at the same point on the airfoil will approximately be:

(A) –3.5

(B) –2.9

(C) –1.5

(D) –0.75

Answer: (C)

29. A solid circular shaft of diameter d is under pure torsion of magnitude T. The maximum tensile stress experienced at any point on the shaft is

(A) 

(B) 

(C) 

(D) 

Answer: (D)

30. A clamped-clamped beam, subjected to a point load P at the midspan, is shown in the figure below. The magnitude of the moment reaction at the two fixed ends of the beam is

(A) PL/2

(B) PL/4

(C) PL/8

(D) PL/16

Answer: (C)

31. Which of the following statement(s) is/are true about the state of a body in plane strain condition?

P: All the points in the body undergo displacements in one plane only, for example the x-y plane, leading to εzz = γxz = γyz = 0.

Q: All the components of stress perpendicular to the plane of deformation, for example the x-y plane, of the body are equal to zero, i.e. σzz = τxz = τyz = 0.

R: Except the normal component, all the other components of stress perpendicular to the plane of deformation of the body, for example the x-y plane, are equal to zero, i.e. σzz ≠ 0,  τxz = τyz = 0.

(A) P only

(B) Q only

(C) P and Q

(D) P and R

Answer: (D)

32. An aircraft with a turbojet engine flies at a velocity of 100 m/s. If the jet exhaust velocity is 300 m/s, the propulsive efficiency of the engine, assuming a negligible fuel-air ratio, is

(A) 0.33

(B) 0.50

(C) 0.67

(D) 0.80

Answer: (B)

33. An aircraft with a turboprop engine produces a thrust of 500 N and flies at 100 m/s. If the propeller efficiency is 0.5, the shaft power produced by the engine is

(A) 50 kW

(B) 100 kW

(C) 125 kW

(D) 500 kW

Answer: (B)

34. An axial compressor that generates a stagnation pressure ratio of 4.0, operates with inlet and exit stagnation temperatures of 300 K and 480 K, respectively. If the ratio of specific heats (𝛾) is 1.4, the isentropic efficiency of the compressor is

(A) 0.94

(B) 0.81

(C) 0.72

(D) 0.63

Answer: (B)

35. A rocket has an initial mass of 150 kg. After operating for a duration of 10 s, its final mass is 50 kg. If the acceleration due to gravity is 9.81 m/s2 and the thrust produced by the rocket is 19.62 kN, the specific impulse of the rocket is

(A) 400 s

(B) 300 s

(C) 200 s

(D) 100 s

Answer: (C)

Q. 26 – Q. 55 carry two marks each.

36. Consider the vector field where The contour integral  is tangent to the contour that encloses the origin, is __________ (accurate to two decimal places).

Answer: (6.25 to 6.35)

37. The magnitude of the x-component of a unit vector at the point (1, 1) that is normal to equi-potential lines of the potential function is _______ (accurate to two decimal places).

Answer: (0.68 to 0.73)

38. Assuming ISA standard sea level conditions (288.16 K, density of 1.225 kg/m3, g = 9.81 m/s2, R = 287 J/(kg-K)), the density (in kg/m3) of air at Leh, which is at an altitude of 3500 m above mean sea level is ________ (accurate to two decimal places).

Answer: (0.85 to 0.88)

39. Consider a cubical tank of side 2 m with its top open. It is filled with water up to a height of 1 m. Assuming the density of water to be 1000 kg/m3, g as 9.81 m/s2 and the atmospheric pressure to be 100 kPa, the net hydrostatic force (in kN) on the side face of the tank due to the air and water is ______ (accurate to two decimal places).

Answer: (9.80 to 9.81)

40. An aircraft with mass of 400,000 kg cruises at 240 m/s at an altitude of 10 km. Its lift to drag ratio at cruise is 15. Assuming g as 9.81 m/s2, the power (in MW) needed for it to cruise is _______ (accurate to two decimal places).

Answer: (62.00 to 63.50)

41. A statically-stable aircraft has a 𝐶𝐿𝛼= 5 (where the angle of attack, α, is measured in radians). The coefficient of moment of the aircraft about the center of gravity is given as 𝐶𝑀,𝑐.𝑔=0.05−4𝛼. The mean aerodynamic chord of the aircraft wing is 1 m. The location (positive towards the nose) of the neutral point of the aircraft from the center of gravity is ______ (in m, accurate to two decimal places).

Answer: (-0.81 to -0.79)

42. An aircraft with a gross weight of 2000 kg, has a speed of 130 m/s at sea level, where the conditions are: 1 atmosphere (pressure), 288 K (temperature), and 1.23 kg/m3 (density). The speed (in m/s) required by the aircraft at an altitude of 9000 m, where the conditions are: 0.31 atmosphere, 230 K, and 0.47 kg/m3, to maintain a steady, level flight is ________ (accurate to two decimal places).

Answer: (209.00 t0 211.00)

43. A pitot probe on an aircraft in a steady, level flight records a pressure of 55,000 N/m2. The static pressure and density are 45,280 N/m2 and 0.6 kg/m3, respectively. The wing area and the lift coefficient are 16 m2 and 2, respectively. The wing loading (in N/m2) on this aircraft is _________ (accurate to one decimal place).

Answer: (18000 to 19440)

44. A spacecraft forms a circular orbit at an altitude of 150 km above the surface of a spherical Earth. Assuming the gravitational parameter, μ = 3.986 × 1014 m3/s2 and radius of earth, RE = 6,400 km, the velocity required for the injection of the spacecraft, parallel to the local horizon, is _______________ (accurate to two decimal places).

Answer: (7.80 to 7.80 (or) 7800 to 7802)

45. Air at 50 kPa pressure and 400 K temperature flows in a duct at Mach 3.0. A part of the flow leaks through an opening on the duct wall into the ambient, where the pressure is 30 kPa. The maximum Mach number achieved in the discharge is _______ (accurate to two decimal places). (Ratio of specific heats of air is 𝛾=1.4).

Answer: (3.30 to 3.40)

46. Consider a 20° half-angle wedge in a supersonic flow at Mach 3.0 at standard sea-level conditions. If the shock-wave angle on the wedge is 36°, the Mach number of the tangential component of the flow post-shock is _______ (accurate to two decimal places).

Answer: (1.90 to 2.20)

47. The boundary layer thickness at the location of a sensor on a flat plate in an incompressible, laminar flow of air is required to be restricted to 1 mm for an effective measurement. If the flow velocity is 20 m/s with 1 bar pressure, 300 K temperature, and 1.789×10˗5 kg/(m-s) viscosity, the maximum distance (in mm) of the sensor location from the leading edge is ________ (accurate to one decimal place).

Answer: (47.0 to 55.0)

48. Gross weight of an airplane is 7000 N, wing area is 16 m2, and the maximum lift coefficient is 2.0. Assuming density at the altitude as 1.23 kg/m3, the stall speed (in m/s) of the aircraft is _________ (accurate to two decimal places).

Answer: (18.80 to 18.90)

49. A thin-walled tube with external radius of 100 mm and wall thickness of 2 mm, is fixed at one end. It is subjected to a compressive force of 1 N acting at a point on the circumference parallel to its length. The maximum normal stress (in kPa) experienced by the structure is _____________ (accurate to two decimal places).

Answer: (-2.50 to -2.20)

50. A 1 m long massless cantilever beam oscillates at 2Hz, while a 60 kg mass is attached at the tip of it. The flexural rigidity of the beam (in kN-m2) is _________________ (accurate to two decimal places)..

Answer: (3.10 to 3.20)

51. A cantilever beam having a rectangular cross-section of width 60 mm and depth 100 mm, is made of aluminum alloy. The material mechanical properties are: Young’s modulus, E = 73 GPa and ultimate stress, σu =480 MPa. Assuming a factor of safety of 4, the maximum bending moment (in kN-m) that can be applied on the beam is _____ (accurate to one decimal place).

Answer: (12.0 to 12.0)

52. The components of stress in a body under plane stress condition, in the absence of body forces, is given by:

𝜎𝑥𝑥=𝐴𝑥2; 𝜎𝑦𝑦= 12𝑥2−6𝑦2 and 𝜎𝑥𝑦=12𝑥𝑦.

The coefficient, A, such that the body is under equilibrium is _____ (accurate to one decimal place).

Answer: (-6.0 to -6.0)

53. An axial compressor rotor with 50 % degree of reaction, operates with an axial velocity of 200 m/s. The absolute flow angle at the inlet of the rotor is 22° with reference to the axial direction. If the axial velocity is assumed to remain constant through the rotor, the magnitude of the relative velocity (in m/s) at the rotor exit is __________ (accurate to one decimal place).

Answer: (215.0 to 216.5)

54. The relative velocity of air leaving a straight radial impeller of a centrifugal compressor is 100 m/s. If the impeller tip speed is 200 m/s, for a slip free operation, the absolute velocity (in m/s) at the impeller exit is _________ (accurate to one decimal place).

Answer: (222.0 to 225.0)

55. An aircraft wind tunnel model, having a pitch axis mass moment of inertia (Iyy) of 0.014 kg-m2, is mounted in such a manner that it has pure pitching motion about its centre of gravity, where it is supported through a frictionless hinge. If the pitching moment (M) derivative with respect to angle of attack (α), denoted by ‘Mα’, is -0.504 N-m/rad and the pitching moment (M) derivative with respect to pitch rate (q), denoted by ‘Mq’, is -0.0336 N-m/(rad/s), the damping ratio of the resulting motion due to an initial disturbance in pitch angle is approximately _________ (accurate to three decimal places).

Answer: (0.195 to 0.205)

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