Combined Defence Service Exam ( UPSC CDS EXAM )

Complete information of UPSC Combined Defence Service Exam i.e CDS Exam

cds examA Combined Defence Service Exam which is also known as CDS exam, is one of the most popular competitive exam in India for the candidates who wants to join Defence Services.

What is CDS Exam ?

Union Public Service Commission conducts the Combined Defence Service Examination (CDS) in India for the recruitment of Officers in Indian Military, Indian Navy and Indian Airforce as well as the Officers in Officers training Academy. The eligible candidates may apply for the examination for getting recruited in Indian Arm Forces. Check your eligibility and qualification in this blog.

Who can Apply for the Combined Defence Service Exam?

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Eligibility Criteria :

  • Nationality :

    A candidate should be citizen of India or a citizen of Nepal or a person of Indian origin who had migrated from Pakistan, Burma, Sri Lanka and East African Countries of Kenya, Uganda, the United Republic of Tanzania, Zambia, Malawi, Zaire and Ethiopia or Vietnam with the intention of permanently settling in India. Provided that the candidates other than the citizen of India the eligibility has been issued by the Government of India. 

  • Age Group, Sex and Maritial status :  (i) For Indian Military Academy : Age group is 20 to 25 years. Unmarried Male candidate can apply.
    (ii) For Indian Naval Academy : Age group is 20 to 25 years. Unmarried Male candidates can apply.
    (iii) For Air Force Academy : Age group is 20 to 24 years. For the candidates who is holding valid and current Commercial Pilot Licence issued by DCGA the age criteria is relaxed upto 26 years.
    (iv) For Officers Training Academy : Age group is 19 to 25 years. Unmarried Male and Female candidates can apply. Issueless widows who have not remarried and issueless divorcees female candidates who have not remarried are also eligible. 
  • Educational Qualification requirement : (i)Degree of a recognised University or equivalent for Indian Military Academy and Officers Training Academy.
    (ii) Degree in Engineering from a recognised University or Institution for Indian Naval Academy.
    (iii) Degree in recognised University with Physics and Mathematics at level 10+2 or Degree in Engineering for Air Force Academy.
    Candidates who are studying in final year/semester can also apply provided they should not have any present backlog upto last year/semester.
  • Medical Fitness : A candidate should be medically fit for applying for Combined defence service exam. Visit for procedure of medical examinations of Officers entry into Army as applicable. Visit for procedure of medical examination of Officers entry into Navy. Visit for procedure of mediacal examination of Officers entry into Air Force. 

How to Apply for Combined Defence Service Exam ?

Candidates are required to apply online for the Combined Defence Service Exam. The advertise of the exam is published in the newspaper and on the UPSC website (
Fee: Candidates who wants to apply for the CDS exam required to pay a fee of Rs 200/-, Either by depositing money in SBI Bank or by online mode by using Visa/Master/Rupay Credit/Debit Card/ UPI Payment or by using internet banking. Female/SC/ST candidates are exempted from payment of fee.

How to prepare for Combined Defence Service Exam ?

If you are a candidate who wants to apply for the Combined Defence Service Exam, you must be Graduate from a University or have appeared in a Final Year of Graduation with no backlogs in any subject.

Proper preparation : Proper preparation is very necessary for getting success in any exam. So while getting ready for CDS exam, you should check out the syllabus. After understanding the syllabus prepare yourself according to the syllabus. Proper preparation can help you to reduce stress and improve your performance.

Practise test : Familiarise yourself with the exam format by practising the mock test. If you get the proper idea of the exam format, it will help you to improve you performance in a great way. So find out the test material for the exam and practise the test as much as you can.

Discussion : Discuss the various methods students use to prepare for the exam. Evaluate the effectiveness of each methods and find out which method is best for you. Talking with the person who have already cracked the exam will help you to boost your confidence.   

Scheme and Syllabus of CDS Exam

The Combined Defence Service Exam comprises of Two Stages.

  1. Objective Type Written Exam
  2. Interview for intelligence and personality test.

For the Admission to the Officers Training Academy there are two subjects in objective type written examination.

  • English  (2 hours, 100 marks)
  • General Knowledge (2 hours, 100 marks)

For the Admission to the Indian Military Academy, Indian Naval Academy and Air Force Academy there are three subjects in the objective type written examination.

  • English (2 hours, 100 marks)
  • General Knowledge (2 hours, 100 marks)
  • Elementary Mathematics (2 hours, 100 marks)

Maximum marks allotted for the interview is 200 marks for Officers Training Academy and 300 marks for Indian Military Academy, Indian Naval Academy and Air Force Academy.

The question papers of General Knowledge will be set in Hindi and English. The candidates are not allowed to use any type of electronic device inside the examination hall. 

The questions will be asked in following manner for following subjects :

The questions in English language subject is design to test the understanding of language of the candidates. The candidates are given the comprehensive passages from which questions has been asked. The other questions such as to find out the synonyms and antonyms for the given words  are also included. The standard of paper will be such as answers may be expected from the candidates of graduate of an Indian University.

The question in General Knowledge paper include the knowledge of current affaire and events and the matters of everyday observation and answer may be expected from educated person who had not made a special study of any scientific subject. This paper will also include the questions on History of India and Geography of a nature which candidate should be able to answer without any special study.


Number System—Natural numbers, Integers, Rational and Real numbers. Fundamental operations, addition, subs-traction, 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 ×, cosine ×, Tangent × when 0° < × < 90° Values of sin ×, cos × and tan ×, for × = 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 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.