March 27, 20269 min read

CDS Exam Pattern 2026: Paper-Wise Syllabus, Marks Distribution and SSB Interview Process

Complete CDS exam pattern guide covering IMA, INA, AFA, and OTA entries with paper-wise syllabus, marks distribution, SSB interview 5-day process, 15 Officer-Like Qualities, and CDS vs NDA comparison.

CDS exam CDS pattern SSB interview IMA OTA defence exams UPSC CDS

The Combined Defence Services exam is your gateway to becoming an officer in the Indian Army, Navy, and Air Force — as a graduate. Unlike NDA which is for 12th pass candidates, CDS is specifically designed for college graduates who want to serve as commissioned officers.

Here's everything you need to know about the CDS exam pattern, SSB interview process, and how to prepare for each stage.

CDS Exam Overview

Parameter	Details
Conducting Body	UPSC (Union Public Service Commission)
Frequency	Twice a year — CDS I (February) and CDS II (September)
Entries	IMA (Army), INA (Navy), AFA (Air Force), OTA (Army — Short Service)
Eligibility	Graduate from recognized university (age 20-25 for IMA/INA/AFA, 20-27 for OTA)
Gender	IMA/INA/AFA: Male only; OTA: Male and Female both
Selection	Written Exam + SSB Interview
Training Duration	IMA: 18 months; INA: varies; AFA: 3 years; OTA: 49 weeks

Key fact: CDS has no negative marking in the written exam — this is unique among major UPSC exams. This changes your strategy significantly.

Written Exam Pattern: IMA, INA, and AFA

Candidates applying for IMA (Indian Military Academy), INA (Indian Naval Academy), and AFA (Air Force Academy) take three papers:

Paper	Subject	Questions	Marks	Duration
Paper I	English	120	100	2 hours
Paper II	General Knowledge	120	100	2 hours
Paper III	Elementary Mathematics	100	100	2 hours
Total	340	300	6 hours

Paper I: English (100 marks)

The English paper tests comprehension, grammar, and vocabulary at a graduate level.

Topics covered:

Reading Comprehension passages (2-3 passages with 5-8 questions each)
Spotting Errors in sentences
Sentence Improvement / Correction
Synonyms and Antonyms
Idioms and Phrases
Fill in the Blanks (vocabulary and grammar)
Ordering of Sentences / Para Jumbles
One-word Substitution
Cloze Test

Difficulty level: Moderate — comparable to SSC CGL Tier II English. Regular reading of newspapers and magazines is sufficient preparation.

Paper II: General Knowledge (100 marks)

GK covers a broad range with emphasis on current events and basic science.

Topic breakdown:

Topic	Approximate Weightage	Key Areas
History	15-20%	Modern India (freedom movement, post-independence), Ancient & Medieval basics
Geography	15-20%	Indian & World Geography, climate, rivers, natural resources
Polity	15-20%	Indian Constitution, governance, Parliament, judiciary
Economics	10-15%	Budget, planning, GDP, inflation, international organizations
Current Affairs	15-20%	Last 12 months — national and international events
General Science	10-15%	Physics, Chemistry, Biology basics
Defence-related	5-10%	Military exercises, defence deals, appointments

Paper III: Elementary Mathematics (100 marks)

The Maths paper covers topics up to Class 10-12 level. Don't let "elementary" fool you — the questions test application, not just formulas.

Topics:

Number System, HCF/LCM
Fundamental Operations (Fractions, Decimals, Square Roots)
Percentage, Profit & Loss, Simple/Compound Interest
Ratio & Proportion, Averages
Time & Work, Time & Distance
Algebra (basic equations, factorization, quadratic equations)
Geometry (lines, angles, triangles, circles, quadrilaterals)
Mensuration (area, volume, surface area of 2D and 3D shapes)
Trigonometry (heights and distances, trigonometric ratios, identities)
Statistics (mean, median, mode, frequency distribution, histograms)

Written Exam Pattern: OTA (Officers Training Academy)

OTA candidates take only two papers — no Mathematics.

Paper	Subject	Questions	Marks	Duration
Paper I	English	120	100	2 hours
Paper II	General Knowledge	120	100	2 hours
Total	240	200	4 hours

The English and GK papers for OTA are the same as IMA/INA/AFA. This makes OTA a viable option for candidates who are weak in Mathematics.

No Negative Marking: Strategy Implications

Since CDS has zero negative marking, your approach should be different from NDA or SSC:

Attempt every question — there's no penalty for wrong answers
Eliminate and guess: Even if you can narrow down to 2 options, guessing gives you a 50% chance at free marks
Don't leave any question blank — this is the single most important strategy tip for CDS
Time management focus shifts: Instead of accuracy, focus on attempting all questions within time

Expected safe scores (approximate, varies by year):

IMA: 110-120 out of 300
INA: 105-115 out of 300
AFA: 120-130 out of 300
OTA: 90-100 out of 200

These cutoffs are relatively low because the SSB interview carries significant weight.

SSB Interview: The 5-Day Process

The SSB (Services Selection Board) interview is where the real selection happens. It's a 5-day assessment spread across multiple tests.

Day	Activity	What's Tested
Day 1	Screening: OIR (Officer Intelligence Rating) + PPDT (Picture Perception & Description Test)	Basic intelligence, communication, group behavior
Day 2	Psychology Tests: TAT (Thematic Apperception Test) + WAT (Word Association Test) + SRT (Situation Reaction Test) + SD (Self-Description)	Personality traits, decision-making, self-awareness
Day 3	GTO (Group Testing Officer) Tasks — Part 1: GD, GPE, PGT, HGT, Snake Race	Leadership, teamwork, physical fitness
Day 4	GTO Tasks — Part 2: Individual Obstacles, Command Task, FGT + Personal Interview	Initiative, courage, communication under pressure
Day 5	Conference: All assessors meet, candidate appears briefly	Final assessment, clarification of doubts

SSB Marks Distribution

Entry	Written Exam Marks	SSB Interview Marks	Total
IMA	300	300	600
INA	300	300	600
AFA	300	300	600
OTA	200	200	400

The SSB interview carries equal weight to the written exam (or even more proportionally for OTA). This means a candidate with average written scores but an excellent SSB performance can still get selected.

The 15 Officer-Like Qualities (OLQs)

The SSB tests these 15 qualities, grouped into 4 factors:

Factor 1 — Planning & Organizing: Effective Intelligence, Reasoning Ability, Organizing Ability, Power of Expression Factor 2 — Social Adjustment: Social Adaptability, Cooperation, Sense of Responsibility Factor 3 — Social Effectiveness: Initiative, Self-Confidence, Speed of Decision, Ability to Influence the Group, Liveliness Factor 4 — Dynamic: Determination, Courage, Stamina

You don't need to be exceptional in all 15 — assessors look for a balanced personality with a minimum threshold across all qualities.

CDS vs NDA: Comparison

Parameter	CDS	NDA
Eligibility	Graduate (any stream)	12th pass (10+2)
Age	20-25 (IMA), 20-27 (OTA)	16.5-19.5
Conducting Body	UPSC	UPSC
Negative Marking	No	Yes (1/3 marks deducted)
Maths Paper	Elementary (Class 10-12)	Advanced (Class 11-12)
Training	IMA: 18 months	NDA: 3 years + 1 year at IMA
Women Eligible	OTA only	No
Frequency	Twice a year	Twice a year
Final Rank	Lt/Sub-Lt/Fg Off after training	Same (but younger officers)

Key difference: CDS produces officers who are older (23-27 at commissioning) while NDA produces younger officers (22-23). Both reach the same rank, but NDA cadets have a slight seniority advantage due to earlier commissioning.

Eligibility Details

Entry	Education	Age (as on date specified)	Marital Status
IMA	Any graduate	20-25 years	Unmarried males
INA	Engineering degree (BE/BTech)	20-25 years	Unmarried males
AFA	Any graduate with Physics & Maths in 10+2 OR Engineering degree	20-24 years	Unmarried males
OTA (Men)	Any graduate	20-27 years	Married/Unmarried males
OTA (Women)	Any graduate	20-27 years	Married/Unmarried females

Important: Final year students can also apply provided they submit proof of graduation before the course commencement date.

Preparation Strategy

For Written Exam (3-4 months):

English: Read editorials daily + practice previous year CDS papers
GK: Lucent's GK (static) + monthly current affairs magazine
Maths: RS Aggarwal or Pathfinder by Arihant — focus on Geometry and Mensuration (highest weightage)

For SSB Interview (ongoing):

Read "Let's Crack SSB Interview" by Dr. NK Natarajan
Practice speaking in front of a mirror and in group settings
Stay updated on current affairs and defence news
Physical fitness is essential — start a running and exercise routine early

FAQ

Can commerce/arts graduates apply for CDS?

Yes. IMA and OTA accept graduates from any stream — Arts, Commerce, Science, Engineering, anything. INA requires an engineering degree, and AFA requires Physics and Maths in 10+2. So if you're a BA or BCom graduate, IMA and OTA are your options.

What is the SSB success rate?

Roughly 5-10% of candidates who appear for SSB get recommended. The screening on Day 1 eliminates about 60-70% of candidates. Among those who make it past screening, approximately 20-30% eventually get recommended. These numbers vary by SSB center and batch.

Can I apply for multiple entries (IMA + OTA) in the same CDS exam?

Yes. You can apply for IMA, INA, AFA, and OTA simultaneously in one application (provided you meet the eligibility for each). If you qualify the written for multiple entries, you'll attend separate SSBs for each.

Is CDS easier than NDA?

The written exam is easier because there's no negative marking and the Maths is elementary level. However, the SSB interview standard is the same, and the competition includes mature graduates who may be more articulate and confident. Overall, CDS written is easier but SSB competition is comparable.

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