# JEE Advanced Past Exam 2019 Paper-1 Question Paper With Answer Key

JEE (ADVANCED) 2019 PAPER-1

PART-1 PHYSICS

SECTION 1 (Maximum Marks: 12)

• This Section contains Four (04) Questions.

• Each question has FOUR options. ONLY ONE of these four options is the correct answer.

• For each question, Choose the option corresponding to the correct answer.

• Answer to each question will be evaluated according to the following marking scheme:

Full Marks : +3 If ONLY the correct option is chosen;

Zero Marks : 0 If none of the options is chosen (i.e. the question is unanswered)

Negative Marks : −1 In all other cases.

1. Consider a spherical gaseous cloud of mass density ρ (r) in free space where r is the radial distance from its center. The gaseous cloud is made of particles of equal mass m moving in circular orbits about the common center with the same kinetic energy K. The force acting on the particles is their mutual gravitational force. If ρ(r) is constant in time, the particle number density n(r) = ρ(r)/m is

(A)  (B) (C) (D) 2. A thin spherical insulating shell of radius R carries a uniformly distributed charge such that the potential at its surface is V0. A hole with a small are α4πR2 (α<<1) is made on the shell without affecting the rest of the shell. Which one of the following statements is correct?

(A)  The potential at the center of the shell is reduced by 2αV0

(B)  The magnitude of electric field at the center of the shell is reduced by (C)  The ratio of the potential at the center of the shell to that of the point at from center towards the hole will be (D)  The magnitude of electric at a point, located on all in passing through the hole and shell’s center, on a distance 2R from the center of the spherical shell will be reduced by 3. A current carrying wire heats a metal rod. The wire provides a constant power (P) to the rod. The metal rod is enclosed in an insulated container. It is observed that the temperature (T) in the metal rod changes with time (t) as

T(t) = T0(1+βt1/4),

where β is a constant with appropriate dimension while T0 is a constant with dimension of temperature. The heat capacity of the metal is,

(A) (B) (C) (D) 4. In a radioactive sample, nuclei either decay into stable nuclei with decay constant 4.5 × 1010 per year or into stable nuclei with decay constant 0.5 × 1010 per year. Given that in this sample all the stable nuclei are produced by the nuclei only. In time t × 109 year, if the ratio  of the sum of stable nuclei to the radioactive nuclei is 99, the value of t will be, [Given : In 10 = 2.3]

(A)  1.15

(B)  9.2

(C)  2.3

(D)  4.6

SECTION 2 (Maximum Marks : 32)

• This section contains EIGHT (08) questions.

• Each question has FOUR options. ONE OR MORE THAN ONE of these four option(s) is(are) correct answer(s).

• For each question, choose the option(s) corresponding to (all) the correct answer(s).

• Answer to each question will be evaluated according to the following marking scheme:

Full Marks : +4 If only (all) the correct option(s) is(are) chosen.

Partial Marks : +3 If all the four options are correct but ONLY three options are chosen;

Partial Marks : +2 If three or more options are correct but ONLY two options are chosen and both of which are correct;

Zero Marks : 0 If none of the options is chosen (i.e. the question is unanswered);

Negative Marks : -1 In all other cases.

• For example, in a question, if (A), (B) and (D) are the ONLY three options corresponding to correct answers, then

choosing ONLY (A), (B) and (D) will get +4 marks;

choosing ONLY (A) and (B) will get +2 marks;

choosing ONLY (A) and (D) will get +2 marks;

choosing ONLY (B) and (D) will get +2 marks;

choosing ONLY (A) will get +1 mark;

choosing ONLY (B) will get +1 mark;

choosing ONLY (D) will get +1 mark;

choosing no option (i.e. the question is unanswered) will get 0 marks; and choosing any other combination of options will get −1 mark.

5. A cylindrical capillary tube of 0.2 mm radius is made by joining two capillaries T1 and T2 of different materials having water contact angles of 0° and 60°, respectively. The capillary tube is dipped vertically in water in two different configurations, case I and II as shown in figure. Which of the following option(s) is(are) correct? [Surface tension of water = 0.075 N/m, density of water = 1000 kg/m3, take g= 10 m/s2]

(A)  The correction in the height of water column raised in the tube, due to weight of water contained in the meniscus, will be different for both cases.

(B)  For case II, if the capillary joint is 5 cm above the water surface, the height of water column raised in the tube will be 3.75 cm. (Neglect the weight of the water in the meniscus)

(C)  For case I, if the joint is kept at 8 cm above the water surface, the height of water column in the tube will be 7.5 cm. (Neglect the weight of the water in the meniscus)

(D)  For case I, if the capillary joint is 5 cm above the water surface, the height of water column raised in the tube will be more than 8.75 cm. (Neglect the weight of the water in the meniscus)

Answer: (A, B, C)

6. A conducting wire of parabolic shape, initially y = x2, is moving with velocity in a non-uniform magnetic field as shown in figure. If V0, B0, L and β are positive constant and ∆ϕ is the potential difference developed between the ends of the wire, then the correct statement(s) is/are: (A) (B) (C)  |∆ϕ| remains the same if the parabolic wire is replaced by a straight wire, y = x initially, of length √2 L

(D)  |∆ϕ| is proportional to the length of the wire projected on the y-axis.

Answer: (B, C, D)

7. In the circuit shown, initially there is no charge on capacitors and keys S1 and S2 are open. The values of the capacitors are C1 = 10 μF, C2 = 30 μF and C3 = C4 = 80 μF. Which of the statement(s) is/are correct?

(A)  At time t = 0, the key S1 is closed, the instantaneous current in the closed circuit will be 25 mA.

(B)  If key S1 is kept closed for long time such that capacitors are fully charged, the voltage across the capacitor C1 will be 4 V.

(C)  The key S1 is kept closed for long time such that capacitors are fully charged. Now key S2 is closed, at this time, the instantaneous current across 30 Ω resistor ( between points P and Q) will be 0.2 A (round off to 1st decimal place).

(D)  If key S1 is kept closed for long time such that capacitors are fully charged, the voltage difference between points P and Q will be 10 V.

8. A charged shell of radius R carries a total charge Q. Given Φ as the flux of electric field through a closed cylindrical surface of height h, radius r and with its center same as that of the shell. Here, center of the cylinder is a point on the axis of the cylinder which is equidistant from its top and bottom surfaces. Which of the following option(s) is/are correct?

0 is the permittivity of free space]

(A)  If h > 2R and r > R then Φ = Q/ϵ0

(B)  If h < 8R/5 and r = 3R/5 then Φ = 0

(C)  If h > 2R and r = 3R/5 then Φ = Q/5ϵ0

(D)  If h > 2R and r = 4R/5 then Φ = Q/5ϵ0

Answer: (A, B, C)

9. One mole of a monatomic ideal gas goes through a thermodynamic cycle, as shown in the volume versus temperature (V-T) diagram. The correct statement(S) is/are:

[R is the gas constant] (A)  Work done in this thermodynamic cycle (B)  The above thermodynamic cycle exhibits only isochoric and adiabatic processes.

(C)  The ratio of heat transfer during processes (D)  The ratio of heat transfer during processes 10. A thin convex lens is made of two materials with refractive indices n1 and n2, as shown in figure. The radius of curvature of the left and right spherical surface are equal. f is the focal length of the lens when n1 = n2 = n. The focal lengths is f + ∆f when n1 = n and n2 = n + ∆ Assuming ∆n << (n – 1) and 1 < n < 2, the correct statement(s) is/are, (A) (B)  For n = 1.5, ∆n = 103 and f = 20 cm, the value of |∆f| will be 0.02 cm (round off to 2nd decimal place).

(C) (D)  The relation between remains unchanged if both the convex surfaces are replaced by concave surfaces of the same radius of curvature.

Answer: (B, C, D)

11. Let us consider a system of units in which mass and angular momentum are dimensionaless. If length has dimension of L, which of the following statement(s) is/are correct?

(A)  The dimension of linear momentum is L1

(B)  The dimension of energy is L2

(C)  The dimension of force is L3

(D)  The dimension of power is L5

Answer: (A, B, C)

12. Two identical moving coil galvanometer have 10 Ω resistance full scale deflection at 2 μA current. One of them is converted into a voltmeter of 100 mV full scale reading and the other into an Ammeter of 1mA full scale current using appropriate resistors. These are then used to measure the voltage and current in the Ohm’s law experiment with R = 1000 Ω resistor by using an ideal cell. Which of the following statement(s) is/are correct?

(A)  The resistance of the Voltmeter will be 100 kΩ

(B)  The resistance of the Ammeter will be 0.02 Ω (round off to 2nd decimal place)

(C)  The measured value of R will be 978 Ω < R < 982 Ω

(D)  If the ideal cell is replaced by a cell having internal resistance of 5 Ω then the measured value of R will be more than 1000 Ω

SECTION-3 (Maximum Marks : 18)

• This section contains SIX (06) questions. The answer to each question is a NUMERICAL VALUE.

• For each question, enter the correct numerical value of the answer using the mouse and the on-screen virtual numeric keypad in the place designated to enter the answer. If the numerical value has more than two decimal places, truncate/round-off the value to TWO decimal places.

• Answer to each question will be evaluated according to the following marking scheme:

Full Marks : +3 If ONLY the correct numerical value is entered;

Zero Marks : 0 In all other cases.

13. A particle is moved along a path AB-BC-CD-DE-EF-FA, as shown in figure, in presence of a force where x and y are in meter and α = −1 Nm1. The work done on the particle by this force will be _____Joule. 14. A block of weight 100 N is suspended by copper and steel wires of same cross sectional area 0.5 cm2 and, length √3 m and 1 m, respectively. Their other ends are fixed on a ceiling as shown in figure. The angles subtended by copper and steel wires with ceiling are 30° and 60°, respectively. If elongation in copper wire is (∆lC) and elongation in steel wire is (∆lS), then the ratio  15. A train S1, moving with a uniform velocity of 108 km/h, approaches another train S2 standing on a platform. An observer O moves with a uniform velocity of 36 km/h towards S2, as shown in figure. Both the trains are blowing whistles of same frequency 120 Hz. When O is 600 m away from S2 and distance between S1 and S2 is 800 m, the number of beats heard by O is______.

[Speed of the sound = 330 m/s] Answer: ((7.00 to 10.00)

16. A parallel plate capacitor of capacitance C has spacing d between two plates having area A. The region between the plates is filled with N dielectric layers, parallel to its plates, each with thickness The dielectric constant of the mth layer is For a very large N (> 103), the capacitance C is The value of α will be _______. [ϵ0 is the permittivity of free space]

Answer: ((0.99 to 1.01))

17. A liquid at 30°C is poured very slowly into a Calorimeter that is at temperature of 110° The boiling temperature of the liquid is 80°C. It is found that the first 5 gm of the liquid completely evaporates. After pouring another 80 gm of the liquid the equilibrium temperature is found to be 50°C. The ratio of the Latent heat of the liquid to its specific heat will be______°C.

[Neglect the heat exchange with surrounding]

18. A planar structure of length L and width W is made of two different optical media of refractive indices n1 = 1.5 and n2 = 1.44 as shown in figure. If L >>W, a ray entering from end AB will emerge from end CD only if the total internal reflection condition is met inside the structure. For L = 9.6 m, if the incident angle θ is varied, the maximum time taken by a ray to exit the place CD is t × 109 s, where t is ______.

[Speed of light c = 3 × 108 m/s] Answer: (49 to 51)

JEE (ADVANCED) 2019 PAPER 1

PART-II CHEMISTRY

SECTION 1 (Maximum Marks: 12)

• This Section contains Four (04) Questions.

•Each question has FOUR options. ONLY ONE of these four options is the correct answer.

• For each question, Choose the option corresponding to the correct answer.

• Answer to each question will be evaluated according to the following marking scheme:

Full Marks : +3 If ONLY the correct option is chosen;

Zero Marks : 0 If none of the options is chosen (i.e. the question is unanswered)

Negative Marks : −1 In all other cases.

1. The green colour produced in the borax bead test of chromium (III) salt is due to

(A)  Cr(BO2)3

(B)  Cr2(B4O7)3

(C)  Cr2O3

(D)  CrB

2. Calamine, malachite, magnetite and cryolite, respectively, are

(A)  ZnSO4, CuCO3, Fe2O3, AlF3

(B)  ZnSO­4, Cu(OH)2, Fe3O4, Na3AlF6

(C)  ZnCO3, CuCO3∙Cu(OH)2, Fe3O4, Na3AlF6

(D)  ZnCO3, CuCO3, Fe2O3, Na3AlF6

3. Molar conductivity (Λm) of aqueous solution of sodium stearate, which behaves as a strong electrolyte, is recorded at varying concentrations (c) of sodium stearate. Which one of the following plots provides the correct representation of micelle formation in the solution?

(A) (B) (C) (D) 4. The correct of acid strength of the following carboxylic acids is (A)  III > II > I > IV

(B)  I > II > III > IV

(C)  I > III > II > IV

(D)  II > I > IV > III

SECTION 2 (Maximum Marks : 32)

• This section contains EIGHT (08) questions.

• Each question has FOUR options. ONE OR MORE THAN ONE of these four option(s) is(are) correct answer(s).

• For each question, choose the option(s) corresponding to (all) the correct answer(s).

• Answer to each question will be evaluated according to the following marking scheme:

Full Marks : +4 If only (all) the correct option(s) is(are) chosen.

Partial Marks : +3 If all the four options are correct but ONLY three options are chosen;

Partial Marks : +2 If three or more options are correct but ONLY two options are chosen and both of which are correct;

Zero Marks : 0 If none of the options is chosen (i.e. the question is unanswered);

Negative Marks : -1 In all other cases.

• For example, in a question, if (A), (B) and (D) are the ONLY three options corresponding to correct answers, then

choosing ONLY (A), (B) and (D) will get +4 marks;

choosing ONLY (A) and (B) will get +2 marks;

choosing ONLY (A) and (D) will get +2 marks;

choosing ONLY (B) and (D) will get +2 marks;

choosing ONLY (A) will get +1 mark;

choosing ONLY (B) will get +1 mark;

choosing ONLY (D) will get +1 mark;

choosing no option (i.e. the question is unanswered) will get 0 marks; and choosing any other combination of options will get −1 mark.

5. A tin chloride Q undergoes the following reactions (not balanced)

Q + Cl → X

Q + Me3N → Y

Q + CuCl2 → Z + CuCl

X is an monoanion having pyramidal geometry. Both and Y and Z are neutral compounds. Choose the correct option(s)

(A)  The central atom in X is sp3 hyrbridized

(B)  There is a coordinate bond in Y

(C)  The oxidation state of the central atom in Z is +2

(D)  The central atom in Z has one lone pair of electrons

6. Fusion of MnO2 with KOH in presence of O2 produces a salt W. Alkaline solution of W upon electrolytic oxidation yields another salt X. The manganese containing ions present in W and X. respectively, are Y and Z. Correct statement(s) is (are)

(A)  In aqueous acidic solution, Y undergoes disproportionation reaction to give Z and MnO2

(B)  Both Y and Z are coloured and have tetrahedral shape

(C)  Y is diamagnetic in nature while Z is paramagnetic

(D)  In both Y and Z, π-bonding occurs between p-orbitals of oxygen and d-orbitals of manganese

Answer: (A, B, D)

7. Choose the reaction(s) from the following options, for which the standard enthalpy of reaction in equal to the standard enthalpy of formation.

(A)  2H2(g) + O2(g) → 2H2O (l)

(B)  2C (g) + 3H2 (g) → C2H6 (g)

(C) (D) 8. Which of the following statement(s) is(are) correct regarding the root mean square speed (Urms) and average translational kinetic energy (εav) of a molecule in a gas at equilibrium?

(A)  Urms is doubled when its temperature is increased four times

(B)  εav is doubled when its temperature is increased four times

(C)  εav at a given temperature does not depend on its molecular mass

(D)  Urms inversely proportional to the square root of its molecular mass

Answer: (A, C, D)

9. Each of the following options contains a set of four molecules. Identify the option(s) where all four molecules possess permanent dipole moment at room temperature.

(A)  BeCl2, CO2, BCl3, CHCl3

(B)  NO2, NH3, POCl3, CH3Cl

(C)  BF3, O3, SF6, XeF6

(D)  SO2, C6H5Cl, H2Se, BrF5

10. In the decay sequence, x1, x2, x3 and x4 are particles/radiation emitted by the respective isotopes. The correct option(s) is(are)

(A)  x1 will deflect towards negatively charged plate

(B)  x2 is β

(C)  x3 is γ-ray

(D)  Z is an isotope of uranium

Answer: (A, B, D)

11. Which of the following statement(s) is(are) true?

(A)  Monosaccharides cannot by hydrolysed to give polyhydroxy aldehydes and ketones

(B)  Oxidation of glucose with bromine water gives glutamic acid

(C)  Hydrolysis of sucrose gives dextrorotatory glucose and laevorotatory fructose

(D)  The two six-membered cyclic hemiacetal forms of D-(+)-glucose are called anomers

Answer: (A, C, D)

12. Choose the correct option(s) for the following set of reactions (A) (B) (C) (D) SECTION-3 (Maximum Marks : 18)

• This section contains SIX (06) questions. The answer to each question is a NUMERICAL VALUE.

• For each question, enter the correct numerical value of the answer using the mouse and the on-screen virtual numeric keypad in the place designated to enter the answer. If the numerical value has more than two decimal places, truncate/round-off the value to TWO decimal places.

• Answer to each question will be evaluated according to the following marking scheme:

Full Marks : +3 If ONLY the correct numerical value is entered;

Zero Marks : 0 In all other cases.

13. Among B2H6, B3N3H6, N2O, N2O4, H2S2O3 and H2S2O8, the total number of molecules containing covalent bond between two atoms of the same kind is _____

14. At 143 K, the reaction of XeF4 with O2F2 produces a xenon compound Y. The total number of lone pair(s) of electrons present on the whole molecule of Y is_____

15. For the following reaction, the equilibrium constant Kc at 298 K is 1.6 × 1017.

Fe2+(aq) + S2 (aq) ⇌ FeS (s)

When equal volumes of 0.06 Fe2+ (aq) and 0.2 M S2− (aq) solutions are mixed, the equilibrium concentration of Fe2+ (aq) is found to be Y × 10−17 M. The value of Y is __________.

Answer: (8.70 to 9.10)

16. On dissolving 0.5 g of a non-volatile non-ionic solute to 39 g of benzene, its vapor pressure decreases from 650 mm Hg to 640 mm Hg. The depression of freezing point of benzene (in K) upon addition of the solute is

(Given data : Molar mass and the molal freezing point depression constant of benzene are 78 g mol1 and 5.12 K kg mol1, respectively)

Answer: (0.97 to 1.06)

17. Consider the kinetic data given in the following table for the reaction A + B + C → Product. The rate of the reaction for [A] = 0.15 mol dm3, [B] = 0.25 mol dm3 and [C] = 0.15 mol dm3 is found to be Y × 105 mol dm3 s1. The value of Y is ______

Answer: (6.70 to 6.80)

18. Schemes 1 and 2 describe the conversion of P to Q and R to S, respectively. Scheme 3 describes the synthesis of T from Q and S. The total number of Br atoms in a molecule of T is ________. JEE (ADVANCED) 2019 PAPER 1

PART-III MATHEMATICS

SECTION 1 (Maximum Marks: 12)

• This Section contains Four (04) Questions.

• Each question has FOUR options. ONLY ONE of these four options is the correct answer.

• For each question, Choose the option corresponding to the correct answer.

• Answer to each question will be evaluated according to the following marking scheme:

Full Marks : +3 If ONLY the correct option is chosen;

Zero Marks : 0 If none of the options is chosen (i.e. the question is unanswered)

Negative Marks : −1 In all other cases.

1. Let S be the set of all complex numbers Z satisfying |z – 2 + i| ≥ √ If the complex number z0 is such that is the maximum of the set then the principal argument of is

(A)  −π/2

(B)  π/4

(C)  π/2

(D)  3π/4

2. Let where α = α (θ) and β = β (θ) are real numbers, and I is the 2 × 2 identity matrix. If

α* is the minimum of the set {α(θ): θ ∈ [0, 2π)} and

β* is the minimum of the set {β(θ): θ ∈ [0, 2π)},

then the value of α* + β* is

(A)  −37/16

(B)  −31/16

(C)  −29/16

(D)  −17/16

3. A line y = mx + 1 intersects the circle (x – 3)2 + (y + 2)2 = 25 at the points P and Q. If the midpoint of the line segment PQ has x-coordinate −3/5, then which one of the following options is correct?

(A)  −3 ≤ m < −1

(B)  2 ≤ m < 4

(C)  4 ≤ m < 6

(D)  6 ≤ m < 8

4. The area of the region {(x, y) ; xy ≤ 8, 1 ≤ y ≤ x2} is

(A) (B) (C)  16 loge 2 – 6

(D) SECTION 2 (Maximum Marks : 32)

• This section contains EIGHT (08) questions.

• Each question has FOUR options. ONE OR MORE THAN ONE of these four option(s) is(are) correct answer(s).

• For each question, choose the option(s) corresponding to (all) the correct answer(s).

• Answer to each question will be evaluated according to the following marking scheme:

Full Marks : +4 If only (all) the correct option(s) is(are) chosen.

Partial Marks : +3 If all the four options are correct but ONLY three options are chosen;

Partial Marks : +2 If three or more options are correct but ONLY two options are chosen and both of which are correct;

Zero Marks : 0 If none of the options is chosen (i.e. the question is unanswered);

Negative Marks : -1 In all other cases.

• For example, in a question, if (A), (B) and (D) are the ONLY three options corresponding to correct answers, then

choosing ONLY (A), (B) and (D) will get +4 marks;

choosing ONLY (A) and (B) will get +2 marks;

choosing ONLY (A) and (D) will get +2 marks;

choosing ONLY (B) and (D) will get +2 marks;

choosing ONLY (A) will get +1 mark;

choosing ONLY (B) will get +1 mark;

choosing ONLY (D) will get +1 mark;

choosing no option (i.e. the question is unanswered) will get 0 marks; and choosing any other combination of options will get −1 mark.

5. Let α and β be the roots of x2 – x – 1 = 0, with α > β. For all positive integers n, define Then which of the following options is/are correct?

(A)  a1 + a2 + a3 + … + an = an+2 – 1 for all n ≥ 1

(B) (C)  bn = αn + βn for all n ≥ 1

(D) Answer: (A, B, C)

6. Let and where a and b are real numbers. Which of the following option is/are correct?

(A)  a + b = 3

(B)  (adj M)1 + adj M1 = −M

(C)  det(adj M‑2) = 81

(D) Answer: (A, B, D)

7. There are three bags B1, B2 and B3. The bag B1 contains 5 red and 5 green balls, B2 contains 3 red and 5 green balls, and B3 contains 5 red and 3 green balls. Bags B1, B2 and B3 have probabilities 3/10, 3/10 and 4/10 respectively of being chosen. A bag is selected random and a ball is chosen at random from the bag. Then which of the following options is/are correct?

(A)  Probability that the chosen ball is green, given that the selected bag is B3, equals 3/8

(B)  Probability that the chosen ball is green equals 39/80

(C)  Probability that the selected bag is B3, given that the chosen ball is green, equals 5/13

(D)  Probability that the selected bag is B3 and the chosen ball is green equals 3/10

8. In a non-right-angled triangle ∆PQR, let p, q, r denote the lengths of the sides opposite to the angles at P, Q, R respectively. The median from R meets the side PQ at S, the perpendicular from P meets the side QR at E, and RS and PE intersect at O. If p = √3, q = 1, and the radius of the circumcircle of the ∆PQR equals 1, then which of the following options is/are correct?

(A)  Length of RS = √7/2

(B)  Area of ∆SOE = √3/12

(C)  Length of OE = 1/6

(D)  Radius of incircle of Answer: (A, C, D)

9. Define the collections {E1, E2, E3, …} of ellipses and {R1, R2, R3, …} of rectangles as follows: R1 : rectangle of largest area, with sides parallel to the axes, inscribed in E1 :

En : ellipse of largest area inscribed in Rn – 1, n > 1;

Rn : rectangle of largest area, with sides parallel to the axes, inscribed in En, n > 1.

Then which of the following options is/are correct?

(A)  The eccentricities of E18 and E19 are NOT equal

(B) for each positive integer N

(C)  The length of latus rectum of E9 is 1/6

(D)  The distance of a focus from the centre in E9 is √5/32

10. Let f : ℝ → ℝ be given by Then which of the following options is/are correct?

(A)  f is increasing on (−∞, 0)

(B)  f ‘ has a local maximum at x = 1

(C)  f is onto

(D)  f ‘ is NOT differentiable at x = 1

Answer: (B, C, D)

11. Let Γ denote a curve y = y(x) which is in the first quadrant and let the point (1, 0) lie on it. Let the tangent to Γ at a point P intersect the y-axis at YP. If PYP has length 1 for each point P on Γ, then which of the following options is/are correct?

(A) (B) (C) (D) 12. Let L1 and L2 denote the lines respectively. If L3 is a line which is perpendicular to both L1 and L2 and cuts both of them, then which of the following options describe(s) L3?

(A) (B) (C) (D) Answer: (A, B, C)

SECTION-3 (Maximum Marks : 18)

• This section contains SIX (06) questions. The answer to each question is a NUMERICAL VALUE.

•For each question, enter the correct numerical value of the answer using the mouse and the on-screen virtual numeric keypad in the place designated to enter the answer. If the numerical value has more than two decimal places, truncate/round-off the value to TWO decimal places.

• Answer to each question will be evaluated according to the following marking scheme:

Full Marks : +3 If ONLY the correct numerical value is entered;

Zero Marks : 0 In all other cases.

13. Let ω ≠ 1 be a cube root of unity. Then the minimum of the set

{|a + bω + cω2|2 : a, b, c distinct non-zero integers} equals ___

14. Let AP(a; d) denote the set of all the terms of an infinite arithmetic progression with first term a and common difference d > 0. If

AP(1; 3) ∩ AP(2; 5) ∩ AP(3; 7) = AP(a; d)

then a + d equals ______

15. Let S be the sample space of all 3 × 3 matrices with entries from the set {0, 1}. Let the events E­1 and E2 be given by

E1 = {A ∈ S : det A = 0} and

E2 = {A ∈ S : sum of entries of A is 7}.

If a matrix is chosen at random from S, then the conditional probability P(E1|E2) equals____

16. Let the point B be the reflection of the point A(2, 3) with respect to the line 8x – 6y – 23 = 0. Let ΓA and ΓB be circles of radii 2 and 1 with centres A and B respectively. Let T be a common tangent to the circles ΓA and ΓB such that both the circles are on the same side of T. If C is the point of intersection of T and line passing through A and B, then the length of the line segment AC is _____

17. If then 27 I2 equals ______

18. Three lines are given by Let the lines cut the plane x + y +z = 1 at the points A, B and C respectively. If the area of the triangle ABC is ∆ then the value of (6∆)2 equals _____