CDS Exam Important Dates, Eligibility Criteria, Exam Pattern, Exam Syllabus - 2021

CDS Exam Important Dates, Eligibility Criteria, Exam Pattern, Exam Syllabus - 2021

he Combined Defence Service (CDS) examination is conducted by the Union Public Service Commission (UPSC). This is one of the most popular exams among the aspirants who aim to serve the nation by joining the Indian Military Academy, Officer Training Academy, Indian Naval Academy, Indian Air Force Academy. The exam is conducted by the commission twice every year in the month of February and September.

Candidates willing to serve the nation can join the defence forces by applying for the CDS examination.

CSD () important Dates

As per the latest UPSC calendar, the important dates are given below-

CDS Examination (Ⅰ), 2021 Important Dates
Date of Notification 28.10.2020
Date of online Application 28.10.2020
Last Date for receipt of Applications 17.11.2020
Date of commencement of Exam 07.02.2021 (SUNDAY)

CDS () Important Dates

CDS Examination (Ⅱ), 2021 Important Dates
Date of Notification 04.08.2021
Date of online Application 04.08.2021
Last Date for receipt of Applications 24.08.2021
Date of commencement of Exam 14.11.2021 (SUNDAY)

The dates of notification, commencement and duration of Examinations/ RTs are liable to alteration at the discretion of the commission.

Eligibility Criteria

The candidates applying for the examination should ensure that they fulfil all the eligibility conditions for admission to the examination.


  • A candidate must be unmarried and must either be
  • A citizen of India, or
  • A subject of Nepal, or
  • A person of Indian origin who has migrated from Pakistan, Burma, Sri Lanka and East African Countries of Kenya, Uganda, the United republic of Tanzania, Zambia, Malawi, Ethiopia, and Zaire (having intention of permanently settling in India).
  • Foreign national (except Gorkha) will be required to produce eligibility certificate issued by Govt. of India

Age, Gender & Marital Status

  • Indian Military Academy – Unwedded male, born between 2nd Jan, 1998 and 1st Jan,2003 solely are eligible.
  • Indian Naval Academy- Unwedded male, born between 2nd Jan, 1998 and 1st Jan, 2003 are eligible.
  • For Air Force Academy- 20 to 24 years as on 1st January 2022 i.e., born between 2nd January 1998 and 1st January 2002.
  • For Officers' Training Academy- (men) unwedded male candidates born between 2nd January 1997 and 1st January 2003 only are eligible.
  • For Officers' Training Academy- (Women Non-Technical Course) Unmarried women, issueless widows and divorcees who have not remarried are eligible. They should have been born between 2nd January 1997 and 1st January 2003.

Educational Qualification

Academy Educational Qualification
Indian Military Academy Graduation or equivalent
India Naval Academy B.E./B. Tech
Air Force Academy Graduation, B.E./ B. Tech (12th with Physics & Maths)
Officers' Training Academy Graduation, B.E./ B. Tech (12th with Physics & Maths)

Physical Standards

Candidates must be physically fit according to physical standards for admission to Combined Defence Services Examination, 2021 as per guidelines by the commission.

CDS 2021, selection procedure

  • Written Test
  • SSB Interview
  • Medical Examination
  • Merit List

Examination Pattern

  • Mode of exam: offline
  • Number of sections: IMA, INA, AFA- three, OTA- Two
  • Nature of questions: Objective type
  • Language: Hindi and English
  • The subjects of the written examination, time allowed and the maximum marks assigned to each subject are as follows-

For Indian Military Academy, Indian Naval Academy and Air Force Academy-

Subject Duration Max. Marks
English 2 hrs 100
General Knowledge 2 hrs 100
Elementary Mathematics 2 hrs 100
Total Marks 300

For Officers’ Training Academy-

Subject Duration Max.Marks Total Marks
English 2 hrs 100 200
General Knowledge 2 hrs 100

There will be negative marking for wrong answers marked by the candidate. One third (0.33) of the marks assigned to that question will be deducted for the marks secured.

CDS 2021 SSB Interview

  • The interview involves two stages as-
  • Stage 1 consists of officer intelligence rating, picture perception, and description test.
  • Stage 2 interview, group testing officer task, psychology test, and the Conference.

Standard and syllabus of the examination


The standard of the papers in Elementary Mathematics will be of matriculation level and other subjects approximately are of graduation level of Indian universities.

CDS Examination 2021, Syllabus


English question paper of CDS Exam includes a passage for answering the questions from the passage. Spotting errors questions, sentence arrangement questions, Synonym & antonyms, selecting words, ordering of words in a sentence, fill in the blank questions, idioms & phrases.

General Knowledge

General Knowledge including current events and everyday observation and experience in their scientific aspects. The paper will also include questions on the History of India and Geography.

General knowledge questions are from general science, Indian polity, history, geography, economics, defence specifics, and static GK

Elementary Mathematics


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, the 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 21 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 (1) Properties of angles at a point, (2) Parallel lines, (3) Sides and angles of a triangle, (4) Congruency of triangles, (5) Similar triangles, (6) Concurrence of medians and altitudes, (7) Properties of angles, sides and diagonals of a parallelogram, rectangle and square, (8) Circles and its properties including tangents and normal, (9) Loci.


Areas of squares, rectangles, parallelograms, triangle, and circle. Areas of figures which can be split up into these figures, 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.

CDS - 2021 Vacancies

Academy Course Reserved For NCC Total Vacancies
Indian Military Academy, Dehradun 152 (DE) Course commencing in January, 2022 13 100
Indian Naval Academy, Ezhimala Course commencing in January, 2022 Executive (General Service)/Hydro 06 26
Air Force Academy, Hyderabad (Pre-Flying) Training Course commencing in January, 2022 i.e., No. 211 F(P) Course. 03 32
Officers’ Training Academy, Chennai (Madras) 115th SSC (Men) (NT) (UPSC) Course commencing in April, 2022 00 170
Officers’ Training Academy, Chennai (Madras) 29th SSC Women (NT) (UPSC) Course commencing in April, 2022 00 17
Total 22 345

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