Combined Defence Services Exam
For those young and courageous individuals who nurture a patriotic sentiment, who are willing to take on any kind of challenges and dedicate their lives to defending the country and its people, the Common Defence Service Test is the path to join the nation’s Defence forces.

Combined Defence Service exam is conducted by UPSC twice every year for recruitment to office cadre of the Army, Navy and Air force. CDS exam is conducted generally in the months of May and October.

Candidates qualifying the written test are interviewed by the Service Selection Board and if finally selected, depending upon the choice given by the candidates and their merit list ranking, are sent to one of the following institutes for orientation training:
(a) Indian Military Academy (IMA), Dehradun
(b) Naval Academy, Goa
(c) Air Force Academy, Begumpet, Hyderabad
(d) Officers Training Academy (OTA), Chennai

Those joining the first three institutes get permanent commission, however cadets passing out of OTA get short service commission. Applicants are required to mention their preferences while filling up the application forms.

Eligibility for CDS examination

Educational Qualifications:
For IMA /OTA : A degree from a recognized University or equivalent.
For Naval Academy: B.Sc. with Physics and/or Mathematics or Bachelor of Engineering.
For Air Force Academy: B.Sc. of a recognized University or equivalent with Physics and/or Mathematics as subjects or Bachelor of Engineering.

Age:
For IMA: Unmarried male candidates between 19-24 years on 1st January or 1st July of the year succeeding the year of examination.
For Naval Academy: Unmarried male candidates between 19-22 years on 1st January or 1st July of the year succeeding; the year of examination.
For Air Force Academy: Unmarried male candidates between 19-23 years on 1st January or 1st July of the year succeeding the year of examination.
For Officers Training Academy: Male candidates (married or unmarried) between 19-25 years on 1st January or 1st July of the year succeeding the year of examination.

Application for CDS Exam

Blank application forms and other particulars are published by UPSC in leading newspapers and Employment News in the month of May/June and November/December. A candidate seeking admission must apply to The Secretary, UPSC, New Delhi on prescribed application form. The application forms are available on payment of the requisite amount from any of the designated post office throughout the country. The examination is held in over 40 centres spread all of the country.

Selection

Examination
Plan of the Examination: The examination comprises:
(a) Written Examination
(b) Interview for intelligence and personality test of such candidates as may be called for interview at one of the Services Selection Centers

Examination Subjects:
The following will be subjects for the written examination (each of 2 hours duration):
(a) For admission to Indian Military Academy, Naval Academy and Air Force Academy:
English – This paper tests the understanding of the English language.
General Knowledge – This tests the general knowledge, current events, history of India, geography of nature and other matters of everyday observation.
Elementary Mathematics – This paper covers arithmetic, algebra, geometry, trigonometry, and statistics.

(b) For Admission to Officers Training Academy (OTA):

English – This paper tests the understanding of the English language.
General Knowledge – This tests the general knowledge, current events, history of India, geography of nature and other matters of everyday observation.

Note:
(i) The papers in all subjects will consist of OBJECTIVE-TYPE (Multiple-Choice questions only). The question papers will be set in English only.
(ii) Each paper will be of 2 hours duration and will carry 100 marks.

Standard of Examination:
The standard of the paper in Elementary Mathematics will be of the Matriculation Examination. The standard of papers in other subjects will approximately be such as may be expected of a graduate of an Indian University.

Centres of examination:
Agartala, Ahmedabad, Aizawl, Allahabad, Bangalore, Bareilly, Bhopal, Calcutta, Chandigarh, Chennai, Cochin, Cuttack, Delhi, Dharwar, Dispur (Guwahati), Gangtok, Hyderabad, Imphal, Itanagar, Jaipur, Jammu, Jorhat, Kohima, Lucknow, Madurai, Mumbai, Nagpur, Panaji (Goa), Patna, Port Blair, Raipur, Sambalpur, Shillong, Shimla, Srinagar, Tirupati, Trivandrum, Udaipur and Vishakhapatnam. The centres and the date of holding the examination are liable to be changed at the discretion of the Commission.
Various concessions, like reservation in posts, are available for NCC cadets appearing in the exam.

Interview and Special Tests
Those who qualify the written test, undergo interview and a series of intelligence and personality tests. The tests, both verbal and non-verbal, are designed not only to judge the mental caliber of the candidate but also to assess his social traits and interest in current affairs.

Personality tests – These tests are as follows
Situation Reaction Test (SRT) – Sixty situations are given and the candidate is required to answer the reactions within 30 minutes.
Thematic Apperception Test (TAT) – A set of 12 pictures are shown and the candidate is required to write a story in 3 minute for each picture.
Word Association Test (WAT) – Sixty words are projected and the candidate is required to make a sentence, in 15 seconds for each word.

Syllabus for CDS

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

General Knowledge
General Knowledge, including knowledge of current events and 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 of History of India and Geography of a nature which candidates should be able to answer without special study.

Elementary Mathematics
Arithmetic:
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, Factorization Theorem, H.C.F. and L.C.M.,

Algebra:
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 and their solutions.
Set language and set notation, Rational expressions and conditional identities, Laws of indices.
Trigonometry:
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.
Geometry:
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. Circle and its properties, including tangents and normals
9. Loci.

Mensuration

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

Statistics-Collection and tabulation of statistical data. Graphical representation-frequency polygons, histograms, bar charts, pie charts, etc. Measures of Central Tendency.

Group test – Group Test is conducted in batches of 8-10 candidates. The test consists of group planning, group discussion, outdoor group tasks. The candidates are asked to take lectures on certain topics.

Physical Standards

Candidates recommended by the Services Selection Board must undergo a medical examination by the Board of Service Medical Officers, and are allowed to go for the training programs only after being declared fit by the medical board.