Combined Defence Service Examination Under UPSC


Combined Defence Service Examination is conducted by the Union Public Service Examination. The exam is conducted twice in every year. The exams are conducted for the office cadre of Army, Navy. The interview is conducted by the Service Selection Board. The Exams is conducted for the following departments,

  • Indian Military Academy, Dehradun
  • Naval Academy, Goa
  • Air Force Academy, Begumpet
  • Officer’s Training Academy, Chennai

              Except Officers training Academy, the others are alone for male candidates. The Indian Military Academy, Naval Academy, Air Force Academy are permanent Service Commission while the other is short Service Commission. The Officers training Academy is for both male and female candidates.

Eligibility Criteria:

       The Candidate must be the

  • Citizen of India
  • Citizen of Nepal
  • Citizen of Bhutan

Before Applying Read Carefully:

  • The candidate applying for Indian Military Office /Office Training Agency must have a degree from a recognized University/Institution
  • The candidate applying for Naval Academy must have an Engineering degree from a Recognized University/Institution
  • The candidate applying for Air Force Academy must have degree in Physics or Engineering degree from a recognized University /Institution
  • The age limit for Indian Military Officer (unmarried male) candidate must be between 19 to 24 years
  • The age limit for Naval Academy (Unmarried male) candidates must be between 19 to 22 years
  • The age limit for Air force Academy (Unmarried male) candidates must be between 19 to 23 years
  • The age limit for Officer’s Training Academy (Unmarried male) candidates must be between 19 to 23 years
  • The women can be unmarried, widow are given preference in Officer’s Training Academy

Selection Procedure:

      The Selection stages are

  • Written Examination
  • Interview



         General Knowledge including knowledge of current events and of such matters of everyday observation and experience in their scientific aspects as may be expected of an educated person who has not made a special study of any scientific subject. The Paper will also include questions on History of India and Geography of a nature which Candidate should be able to answer without special study.



Number System-Natural numbers, Integers, Rational and Real numbers. Fundamental Operations addition, subtraction, multiplication, division, Square roots, Decimal, fractions. Unitary method, time and distance, time and work, percentages, applications to simple and compound interest, profit and loss, ratio and proportion, variation.

Elementary Number Theory- Division algorithm. Prime and composite numbers. Tests of divisibility by 2, 3,4,5,9 and 11. Multiples and factors. Factorisation Theorem. H.C.F. and L.C.M. Euclidean algorithm, Logarithms to base 10, laws of logarithms, use of logarithmic tables.


Basic Operations, simple factors, Remainder Theorem, H.C.F., L.C.M. Theory of polynomials, Solutions of quadratic equations, relation between its roots and coefficients (Only real roots to be considered). Simultaneous linear equations in two unknowns-analytical and graphical solutions. Simultaneous linear in equations in two variables and their solutions. Practical problems leading to two simultaneous linear equations or in equations in two Variables or quadratic equations in one variable & their solutions. Set language and set notation, rational expressions and conditional identities, Laws of indices.


Sine x, cosine x, Tangent x when 0 <x < 90 Values of sin x, cos x and tan x, for x = 0, 30, 45, 60 and 90. Simple trigonometric identities. Use of trigonometric tables. Simple cases of heights and distances.


Lines and angles, Plane and plane figures, Theorems on (i) Properties of angles at a Point(ii) Parallel lines, (iii) Sides and angles of a triangle, (iv) Congruency of triangles, (v) Similar triangles, (vi) Concurrence of medians and altitudes, (vii) Properties of angles, sides and diagonals of a parallelogram, rectangle and square (viii) Circles and its properties including tangents and normal, (ix) Loci.


Areas of squares, rectangles, parallelograms, triangle and circle. Areas of figures which Can be split up into these figures (Field Book), Surface area and volume of cuboids, lateral surface and volume of right circular cones and cylinders, surface area and Volume of spheres.


Collection and tabulation of statistical data, Graphical representation, frequency Polygons, histograms, bar charts, pie charts etc. Measures of central tendency.

Exam Pattern:

         The Exams for Indian Military Officer/Naval Academy/Air Force Academy are of objective type with 100 marks each and 360 minutes time duration. The exam consists of four papers. The officer’s training academy is of objective type with 100 marks for each paper with 360 minutes time duration. The exam consists of three papers. There is penalty for each wrong answer.

How to apply

  • Log onto the official website
  • Fill all the necessary details
  • Upload the photo and signature
  • Agree to the declaration
  • Pay the fees via credit card/debit cardor internet banking
  • Submit the application form
  • Take the printout of the form for reference


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