CDS Exam – Combined Defence Service Exam A to Z Details


It is a combined exam for joining three parts of armed forces i.e. the army, the navy and the air force. It is similar to National Defence Academy (NDA) Exam & it is also conducted twice in a year similar to NDA. The difference is that NDA is conducted by UPSC after 12th  and CDS is conducted after graduation. Final year graduation students can also apply for it but they have to produce the degree till a prefixed date, which is different for different training academies.

After passing cds written exam, candidates are called for SSB interview.  Recommended & medically fit candidates join the Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA) and Officers’ Training Academy (OTA) for training. Candidates selected for PC (permanent commission) join IMA, INA & AFA  whereas short service commission candidates join OTA.

Candidates selected for permanent commission will undergo training for approx.18 months. And candidates selected for short service commission will be trained at OTA for approx.11 months.

Eligibility Criteria for CDS Exam

ACADEMY Age Limits Educational Qualifications
INA 19-22 years B.Sc. with Mathematics & Phyiscs or BE/BTech
AFA 19-23 years                 -do-
IMA 19-24 years Degree of a recognized University or equivalent.
OTA 19-25 years                -do-

Scheme of Examination of CDSE Written Test

Written exam consist of 3 papers i.e. English , General Knowledge & Elementary Mathematics.

A. For Admission to Indian Military Academy, Indian Naval Academy and Air Force Academy.

Subject Duration No. of Question Max. Marks
English 2 Hours 120 100
General Knowledge 2 Hours 120 100
Elementary Mathematics 2 Hours 100 100

B.  For Admission to Officers’ Training Academy

Subject Duration No. of Questions Maximum Marks
English 2 Hours 120 100
General Knowledge 2 Hours 120 100


Subject Duration No. of Questions Max. Marks
English 2 Hours 120 100
General Knowledge 2 hours 120 100

 Marking Scheme of CDSE Exam

Subject Correct Answer Wrong Answer
English +0.83 Marks -0.27  Marks
G.K. +0.83 Marks -0.27  Marks
Elementary Mathematics     +1  Marks -0.33  Marks

Previous Cut Off Marks

The Commission fix qualifying marks for each paper and it varies every time. The cutoffs officially  declared by UPSC are given below.

  CDS II 2012    CDS  I 2013


Minimum qualifying marks in each subject Aggregate marks of last qualified candidate Marks of last recommended candidate Minimum qualifying marks in each subject Aggregate marks of last qualified candidate Marks of last recommended candidate
AFA 12 144 266 15 129 256
IMA 12 114 237 15 102 225
INA 12 108 231 15 75 206
OTA(MEN) 12 76 158 15 72 154
OTA(WOMEN) 12 76 159 15 72 152


  1. Written marks are added to the final All India Merit List.
  2. There is a sectional cut off in CDS  Exam ,which means candidate has to get minimum qualifying marks in each subject.
  3. There is no percentage criteria in degree for CDSE.

 Schedule of Examination

         Particular CDS I CDS II
Date of Notification Nov.        June
Date of Exam Feb.        Sep-Oct
Written Result May-June     Dec.-Jan.
SSB Dates August-Sep. March-April
Merit List of IMA,INA,AFA of OTA Oct.    




Training Starts at IMA,INA,AFA at OTA Jan.    






The standard of paper  will approximately be such as may be expected of a graduate of an Indian University.

The question paper will be designed to test the candidates’ understanding of English and workmanlike use of words.


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.


The standard of the papers in Elementary Mathematics will be of Matriculation level.


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 inequations in two variables and their solutions.

Practical problems leading to two simultaneous linear equations or inequations 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 00 < x < 900 Values of sin x, cos x and tan x, for x =

00, 300, 450, 600 and 900

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 normals, (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.