The Combined Defence Services (CDS) exam, conducted by the Union Public Service Commission (UPSC), is a crucial step for those aspiring to join the Indian Armed Forces. This exam provides entry into the defence services and the exam assesses candidates on their knowledge, aptitude, and physical fitness, requiring a strategic and disciplined approach to preparation. This blog outlines essential tips, strategies, and resources to help aspirants prepare effectively and succeed in the CDS exam.

What is the full form of CDS?

CDS stands for Combined Defence Services, which is a national-level examination conducted by the Union Public Service Commission (UPSC) to recruit officers for the Indian Army, Navy, and Air Force. It is held twice a year and serves as an entry point for candidates aspiring to join:

Indian Military Academy (IMA) – For the Indian Army
Indian Naval Academy (INA) – For the Indian Navy
Air Force Academy (AFA) – For the Indian Air Force
Officers’ Training Academy (OTA) – For the Army (Short Service Commission)

The selection process includes a written exam, SSB interview, and medical examination. Successful candidates undergo training before being commissioned as officers in the armed forces.

CDS Exam - Overview

The CDS Examination is conducted by the Union Public Service Commission (UPSC) to recruit candidates for the Indian Army, Navy, and Air Force. It is one of the most prestigious exams for those aspiring to serve in the Indian Armed Forces as officers.

Key Highlights of the CDS Exam

Feature	Details
Exam Name	Combined Defence Services (CDS) Exam
Conducting Authority	Union Public Service Commission (UPSC)
Frequency	Twice a year – February & September
Purpose	Recruitment for IMA (Indian Military Academy), INA (Indian Naval Academy), AFA (Air Force Academy), and OTA (Officers Training Academy)
Mode of Exam	Offline (Pen & Paper)
Selection Process	Written Exam → SSB Interview → Medical Examination
Eligibility	Unmarried graduates (age and qualification vary by academy)

Important Dates for CDS 2025

Event	CDS I 2025	CDS II 2025
Notification Release	4th December 2024	15th May 2025
Application Start Date	4th December 2024	15th May 2025
Last Date to Apply	3rd January 2025	5th June 2025
Exam Date	16th February 2025	14th September 2025
Result Declaration	28th April 2025	October 2025 (Exact date TBD)

Eligibility Criteria for CDS Exam

The Combined Defence Services (CDS) Exam is conducted by UPSC twice a year to recruit candidates for the Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA), and Officers’

Training Academy (OTA). Below are the detailed eligibility criteria:

1. Nationality

A candidate must be:

An Indian Citizen, OR
A subject of Nepal or Bhutan, OR
A Tibetan refugee who came to India before January 1, 1962, with the intention of permanent settlement, OR
A person of Indian origin (PIO) who has migrated from Pakistan, Sri Lanka, Burma, East African countries (Kenya, Uganda, Tanzania, etc.), or Vietnam with the intention of permanent settlement in India.

2.Age Limit & Marital Status:
Age is calculated as of January 1st or July 1st of the exam year.

Academy	Age Limit	Marital Status
Indian Military Academy (IMA)	18–23 years	Unmarried Male
Indian Naval Academy (INA)	18–23 years	Unmarried Male
Air Force Academy (AFA)	18–23 years	Unmarried Male (Married candidates above 25 years can apply but won’t get accommodation during training)
Officers’ Training Academy (OTA) – Men	19–25 years	Unmarried Male
Officers’ Training Academy (OTA) – Women	19–25 years	Unmarried Female/Widows/Divorcees (who haven't remarried)

3. Educational Qualification

Final-year students can apply, provided they submit their degree before the SSB interview.

Academy	Educational Qualification
Indian Military Academy (IMA)	Bachelor’s degree from a recognised university.
Indian Naval Academy (INA)	Engineering degree from a recognised university/institution.
Air Force Academy (AFA)	(i) Bachelor’s degree with Physics & Mathematics at 10+2 level, OR (ii) B.E./B.Tech (Engineering) degree.
Officers’ Training Academy (OTA)	Bachelor’s degree from a recognised university.

4. Physical & Medical Standards

Candidates must meet the physical and medical standards specified by UPSC. Key points include:

Height Requirements:

Men: Minimum height of 157.5 cm (AFA requires 162.5 cm).
Women: Minimum height of 152 cm for OTA.
Relaxation in Height: Candidates from Gorkhas, Garhwalis, Assamese, Kumaonis, and North-Eastern States get a 5 cm relaxation in height.

Vision Standards:

Army & Navy: 6/6 in one eye and 6/9 in the other (correctable with glasses).
Air Force: 6/6 in both eyes without glasses; myopia should not exceed -3.5D.

5. Number of Attempts

There is no limit on the number of attempts, provided the candidate meets the age and eligibility criteria.

CDS Exam 2025 – Selection Process

The journey to becoming an officer through the CDS Exam involves three key stages, each designed to test different aspects of a candidate’s capabilities.

1. Written Exam

The first stage is a pen-and-paper test conducted by UPSC. The exam pattern varies depending on the academy:

Academy	Subjects	Duration
IMA, INA & AFA	English, General Knowledge, Elementary Mathematics	2 hours per subject
OTA	English, General Knowledge,	2 hours per subject

Each paper has objective-type questions.
Candidates must score minimum qualifying marks to be eligible for the next stage.
Negative marking: 1/3rd mark deducted for every wrong answer.

2. SSB Interview

Candidates who clear the written exam move to the Services Selection Board (SSB) stage, a comprehensive assessment of personality and leadership potential.
It includes:

Screening Tests (Psychological tests & interviews)
Stage I Tests (Intelligence and Personality tests)
Stage II Tests (Group tasks, personal interviews, outdoor exercises)

Only candidates who pass both Stage I and Stage II are recommended for medical examination.

3. Medical Examination

In the final round, candidates undergo a detailed medical check-up to ensure they meet the strict physical and mental standards of the defence forces.
Key checks include:

Physical fitness, height, weight, and chest measurements
Vision, hearing, and dental health
Freedom from chronic illnesses or disabilities

Candidates who successfully clear all three stages – Written Exam, SSB Interview, and Medical Test – earn their place in the training academies.

CDS Exam Syllabus 2025 – Highlights

The Combined Defence Services (CDS) Exam is conducted by UPSC to select candidates for officer positions in the Indian Armed Forces. The syllabus evaluates candidates in English, General Knowledge, and Elementary Mathematics to test language skills, awareness, and analytical ability.

The exam is conducted offline, with objective-type questions and negative marking for incorrect answers.

CDS Exam Overview 2025

Feature	Details
Mode of Exam	Offline (Pen & Paper)
Total Marks	IMA, INA & AFA – 300; OTA – 200
Number of Sections	IMA, INA, AFA – 3; OTA – 2
Language	Hindi & English
Duration	2 hours per section
Question Type	Objective / Multiple Choice
Negative Marking	1/3rd mark deducted for each wrong answer

CDS Exam Subject-Wise Syllabus 2025

The Combined Defence Services (CDS) 2025 exam syllabus focuses on English, General Knowledge, and Elementary Mathematics (for IMA, INA, and AFA) or just English and General Knowledge (for OTA), with key topics including grammar, vocabulary, current affairs, history, geography, science, arithmetic, algebra, geometry, and trigonometry. The syllabus is designed for graduates, with Elementary Mathematics questions based on a Class 10 level.

Subject	Academies	Key Topics
English	All (IMA, INA, AFA, OTA)	Vocabulary (Synonyms, Antonyms, One-word substitution), Grammar (Sentence Correction, Error Spotting), Comprehension, Idioms & Phrases, Paragraph Completion
General Knowledge	All	Current Affairs (National & International), History (Ancient, Medieval, Modern, Indian National Movement), Geography (India & World), Polity (Constitution, Governance, Fundamental Rights), Economy & Social Development, Basic Science (Physics, Chemistry, Biology)
Elementary Mathematics	IMA, INA, AFA	Arithmetic (Percentages, Profit & Loss, Ratio & Proportion, Time & Work, Time & Distance, Simple & Compound Interest, Averages), Algebra (Linear & Quadratic Equations, HCF & LCM), Geometry & Mensuration (Triangles, Circles, Quadrilaterals, Areas, Volumes), Trigonometry (Heights & Distances, Ratios, Identities), Statistics & Probability

OTA Subject-Wise Syllabus 2025

Subject	Key Topics	Duration	Marks
English	Vocabulary (Synonyms, Antonyms, One-word Substitution), Grammar (Error Spotting, Sentence Completion, Fill in the Blanks), Comprehension Passages, Idioms & Phrases, Para Jumbles	2 hours	100
General Knowledge	Current Affairs (National & International), History (Ancient, Medieval, Modern, Indian National Movement), Geography (India & World), Polity (Indian Constitution, Governance, Fundamental Rights), Economy & Social Development, Basic Science (Physics, Chemistry, Biology)	2 hours	100

Note: OTA does not include Mathematics, making it distinct from IMA, INA, and AFA. Candidates should focus on English and GK preparation, practising previous year papers and staying updated with current affairs.

CDS Exam Structure and Pattern

To excel in the Combined Defence Services (CDS) exam, it's essential to have a clear understanding of its structure and pattern. Here’s a detailed breakdown:

CDS Exam Structure:

The written exam comprises three subjects:

English – Tests grammar, vocabulary, and comprehension.
General Knowledge – Covers current affairs, history, geography, and science.
Mathematics (only for IMA, INA & AFA) – Focuses on arithmetic, algebra, and geometry.

Students who clear the written exam proceed to the SSB (Services Selection Board) Interview, which evaluates leadership qualities, communication skills, and psychological aptitude. Finally, a medical examination determines the candidate’s fitness for military service.

CDS Exam Pattern

The CDS exam is divided into written tests and an interview. Here’s the pattern for both:

Written Exam:

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

Subjects	Duration	No. of Questions	Max. Marks
English	2 hours	120	100
General Knowledge	2 hours	120	100
Elementary Mathematics	2 hours	100	100

For Officers Training Academy:

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

CDS Exam Marking System

The CDS exam marking scheme follows a structured pattern, including positive marking for correct answers and penalties for incorrect ones. The table below provides a clear breakdown of the marking system and exam duration for different academies.

Criteria	IMA, INA & AFA	OTA
Marks per Correct Answer	1	1
Negative Marking for Wrong Answer	-0.33 per wrong answer	-0.33 per wrong answer
No Penalty for Unanswered Questions	No deduction	No deduction
Total Exam Duration	6 Hours	4 Hours

CDS Interview Process

After clearing the written exam, candidates are called for the Service Selection Board (SSB) interview, which includes:

Psychological Tests: Assess the candidate's mental fitness.
Group Testing Officer Tasks: Evaluate the candidate’s ability to work in a team.
Personal Interview: An in-depth interview to understand the candidate’s personality and suitability for the armed forces.
Conference: Final assessment and recommendation.

Why Choose CDS Exam?

The CDS exam provides an opportunity to join the Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA), and Officers Training Academy (OTA). It offers a respectable career, job security, adventure, and the honour of serving the nation.

Who conducts the CDS Exam in India?

The Union Public Service Commission (UPSC) conducts the Combined Defence Services (CDS) Exam twice a year to recruit officers for the Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA), and Officers’ Training Academy (OTA). Open to eligible graduates, the selection process includes a written test and a Services Selection Board (SSB) interview assessing leadership, problem-solving, and physical fitness. Qualifying the exam paves the way for a prestigious career in the defence forces.

How to Register for the CDS Exam?

Candidates can register for the CDS exam online through the UPSC official website. Follow these steps to apply:

Step-by-Step Registration Process

1. Visit the Official Website:

Go to upsc.gov.in and click on "Examinations" → "Active Examinations" → "CDS Exam Notification".

2. Complete Part 1 Registration:

Click on "Online Application for Various Exams of UPSC".
Fill in personal details like name, date of birth, email, and mobile number.
Choose your desired academy (IMA, INA, AFA, OTA).

3. Complete Part 2 Registration:

Upload scanned photos, signature, and photo ID proof (JPG format).
Pay the exam fee of ₹200 (except SC/ST & female candidates, who are exempted).
Select your preferred exam centre.

4. Final Submission & Print Application:

Verify all details and submit the form.
Download and print the application receipt for future reference.

Important things to note:

Keep a valid email ID & phone number for updates.
Check eligibility before applying.
Submit the form before the deadline (usually 3-4 weeks after notification).
You will receive the CDS admit card on the UPSC website before the exam date.

CDS Exam Subject-Wise Preparation Strategy

To ace the CDS exam, it’s essential to have a solid preparation strategy for each subject. Here’s a detailed guide to help you prepare effectively:

1. English

Focus on grammar, vocabulary, and comprehension.
Practice reading newspapers, novels, and magazines to improve language skills.
Make a habit of noting down new words and their meanings.
Use flashcards or vocabulary apps for practice.
Solve previous year question papers to get familiar with the question types.

2. General Knowledge

Keep yourself updated with current affairs, national and international events.
Study history, geography, polity, and economics thoroughly.
Read reliable sources like NCERT books, newspapers, and monthly magazines.

3. Mathematics

Focus on basic concepts of arithmetic, algebra, geometry, and trigonometry.
Solve as many mock tests and previous year papers as possible.
Time management is crucial; practice solving questions within a time limit.

How to Start Preparing for CDS exam?

If you're Preparing for the CDS exam, it requires dedication, discipline, and a smart approach. A well-structured study plan is crucial for effective preparation for the CDS exam. Here’s a guide to help you create a comprehensive study plan:

1. Understand the Exam Pattern & Syllabus

Familiarize yourself with the CDS exam structure, subjects, and marking scheme.
Identify key topics for English, General Knowledge, and Mathematics (for IMA, INA & AFA).

2. Set a Realistic Timeline

Divide your preparation into daily, weekly, and monthly targets.
Allocate more time to weaker subjects while maintaining a balanced approach.

3. Follow a Structured Study Routine

Dedicate 5-6 hours daily for effective preparation.
Begin with conceptual learning, followed by problem-solving and revision.

4. Refer to Standard Study Materials

Use NCERT books for basics and standard reference books for in-depth study.
Rely on UPSC-recommended books and previous years' question papers.

5. Focus on General Knowledge & Current Affairs

Read newspapers, magazines, and reliable online sources daily.
Make notes of important events and revise them frequently.

6. Enhance English Language Skills

Improve grammar, vocabulary, and comprehension by reading books and articles.
Practice error spotting, sentence improvement, and reading comprehension exercises.

7. Strengthen Mathematical Concepts

Focus on arithmetic, algebra, geometry, and trigonometry.
Solve numerical problems daily to enhance speed and accuracy.

8. Regular Practice & Mock Tests

Solve previous years' papers to understand question patterns.
Attempt mock tests to improve time management and accuracy.

9. Stay Motivated & Maintain Discipline

Keep a positive mindset and stay committed to your goal.
Take short breaks and maintain a healthy balance between studies and relaxation.

10. Seek Guidance & Join a Study Group

Connect with mentors, coaching institutes, or online forums for additional support.
Discuss doubts and strategies with fellow aspirants to enhance learning.

Important Instructions for the CDS Exam 2025

The Important Instructions for the CDS Exam provide essential guidelines to ensure candidates correctly fill out their answer sheets and handle test booklets. Following these rules carefully helps avoid mistakes that could lead to disqualification or rejection of the answer sheet.

Use Only a Black Ballpoint Pen: Make sure to write your Centre, Subject, and then include the CDS 2025 Test Booklet Series (in brackets), Subject Code, and your Exam Roll Number in the designated area at the top of the answer sheet.
Encode Your Details Carefully: Fill in the circles on the OMR answer sheet for the CDS Subject Code, Booklet Series (A, B, C, or D)and Roll Number.
Report Any Missing Information: If you notice that the Test Booklet series is missing or if your answer sheet is unnumbered, let the invigilator know right away and ask for a replacement booklet or answer sheet.
Accuracy is Key: Be careful! Any mistakes or discrepancies when encoding or filling in details, especially the Roll Number and Booklet Series, could lead to your answer sheet being rejected.
Check the Test Booklet: As soon as you receive the CDS 2025 booklet, check to ensure it has no missing, torn, or unprinted pages. If you find any issues, request a replacement booklet of the same series and subject.
Do Not Write Personal Details: Only write the necessary information on the answer sheet or test booklet. Please refrain from writing your name or any unrelated content, including rough work.
Handle the Answer Sheet with Care: Avoid folding, damaging, or making extra markings on the CDS answer sheet. Also, do not write on the back of the answer sheet.

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Conclusion

Preparing for the CDS exam is a significant step towards achieving your dream of serving as an officer in the armed forces. With dedication, discipline, strategic preparation, and perseverance, you can excel in this competitive exam. Stay focused, manage your time effectively, and maintain a positive mindset. Believe in yourself, and you'll be one step closer to wearing the prestigious uniform!

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