The Combined Defence Services (CDS) Examination is conducted by the Union Public Service Commission (UPSC) for admission to the Indian Military Academy (IMA), Indian Naval Academy (INA), Air Force Academy (AFA) and Officers' Training Academy (OTA), subject to the eligibility requirements for each academy.

CDS 1 2027 Syllabus for IMA, INA, AFA

The CDS 1 2027 syllabus includes English, General Knowledge and Elementary Mathematics. Candidates applying for IMA, INA, and AFA must prepare all three subjects, while OTA candidates must appear for English and General Knowledge in the written examination.

Major Kalshi Classes (MKC), a defence coaching institute established in 2008, supports aspirants preparing for defence examinations. Understanding the syllabus before starting preparation can help candidates prioritise topics, practise previous-year questions and organise revision effectively.

CDS 1 2027 Syllabus: Overview

The CDS written examination consists of objective-type questions. The number of papers depends on the academy selected by the candidate.

Candidates should refer to the official CDS 1 2027 notification for the final examination scheme and instructions.

CDS 1 2027 Exam Pattern

Understanding the examination pattern helps candidates distribute their preparation time according to the marks assigned to each paper.

CDS Exam Pattern for IMA, INA and AFA

CDS Exam Pattern for OTA

The written examination is followed by the SSB interview for candidates who qualify and meet the relevant requirements. The maximum SSB marks are 300 for IMA, INA and AFA, and 200 for OTA.

CDS 1 2027 English Syllabus

The English paper tests candidates' understanding of the language and their ability to use words correctly. UPSC describes the syllabus broadly, so the following topics are useful preparation areas based on the nature of CDS English questions.

Important Topics in the CDS English Syllabus

• Spotting errors
• Sentence improvement
• Sentence completion
• Fill in the blanks
• Synonyms and antonyms
• Vocabulary
• Idioms and phrases
• Ordering of words in sentences
• Ordering of sentences
• Reading comprehension
• Selecting appropriate words
• Grammar and correct usage
• Parts of speech
• Tenses
• Subject-verb agreement
• Active and passive voice
• Direct and indirect speech

These are preparation topics, not a guaranteed question-by-question distribution for CDS 1 2027.

How to Prepare for CDS English

Candidates should practise English regularly instead of leaving the subject for the final weeks. A strong vocabulary, knowledge of grammar and familiarity with sentence structures can help improve accuracy.

Read English newspapers or editorials to improve comprehension and learn words in context. Solve previous-year CDS English papers to understand the question formats and identify recurring weaknesses.

Maintain a notebook of unfamiliar words, grammar rules and frequently repeated mistakes. Regular revision and timed practice can help candidates improve their performance.

CDS 1 2027 General Knowledge Syllabus

The General Knowledge paper assesses awareness of current events and general scientific knowledge, along with topics related to Indian history and geography. Candidates should prepare both static subjects and current affairs.

Important Topics in the CDS GK Syllabus

1. History

• Ancient Indian history
• Medieval Indian history
• Modern Indian history
• Indian national movement
• Important historical events
• Social and religious reform movements
• Important personalities and their contributions

2. Geography

• Physical geography
• Indian geography
• World geography
• Rivers, mountains and plateaus
• Climate and monsoons
• Natural resources
• Agriculture and industries
• Soils and vegetation
• Population and settlements

3. Indian Polity

• Constitution of India
• Fundamental Rights and Duties
• Directive Principles of State Policy
• President and Vice-President
• Parliament
• Prime Minister and Council of Ministers
• Supreme Court and High Courts
• Constitutional bodies
• Centre-state relations
• Local government

4. Economics

• Basic economic concepts
• National income
• Inflation
• Banking and financial institutions
• Budget and taxation
• Unemployment and poverty
• Economic development
• Government schemes and policies

5. Physics

• Motion and force
• Work, energy and power
• Gravitation
• Heat and temperature
• Sound
• Light
• Electricity and magnetism
• Basic scientific instruments

6. Chemistry

• Elements and compounds
• Atoms and molecules
• Acids, bases and salts
• Metals and non-metals
• Chemical reactions
• Fuels and combustion
• Everyday chemistry

7. Biology and General Science

• Human body systems
• Nutrition and vitamins
• Diseases and prevention
• Cells and tissues
• Plant and animal biology
• Environment and ecology
• Scientific discoveries
• Everyday scientific phenomena

8. Current Affairs

• National and international developments
• Defence exercises and developments
• Important appointments
• Awards and honours
• Sports events
• Science and technology
• Space missions
• Important government initiatives
• International organisations and summits

The topics above provide a practical preparation checklist. UPSC does not prescribe a fixed number of questions from each of these areas in the broad GK syllabus.

How to Prepare for CDS General Knowledge

Start with the fundamentals of History, Geography, Polity and Science. These subjects provide a foundation for solving objective questions without relying entirely on memorisation.

Read reliable current-affairs sources regularly and revise important developments. Topic-wise quizzes and previous-year papers can help you understand the level of detail expected in the examination.

Prepare concise notes for important dates, constitutional provisions, scientific concepts and defence-related developments. Revise these notes at regular intervals to improve retention.

CDS 1 2027 Elementary Mathematics Syllabus

The Elementary Mathematics paper is required for candidates applying to IMA, INA and AFA. It tests mathematical understanding, numerical accuracy and the ability to solve problems using fundamental concepts.

The following sections reflect the main units listed in the UPSC CDS syllabus.

1. Arithmetic

Arithmetic covers numerical operations and practical mathematical problems.

Important topics include:

• Number systems
• Natural numbers, integers, rational and real numbers
• Fundamental operations
• Square roots
• Decimal fractions
• Unitary method
• Time and distance
• Time and work
• Percentages
• Simple and compound interest
• Profit and loss
• Ratio and proportion
• Variation

Candidates should practise calculations regularly and learn to identify the correct method for each problem.

2. Elementary Number Theory

The syllabus includes elementary number theory and logarithms.

Important topics include:

• Division algorithm
• Prime and composite numbers
• Divisibility tests
• Multiples and factors
• Factorisation theorem
• Highest Common Factor (HCF)
• Lowest Common Multiple (LCM)
• Euclidean algorithm
• Logarithms to base 10
• Laws of logarithms
• Use of logarithmic tables

A clear understanding of divisibility, factors and logarithmic rules can help candidates solve related questions accurately.

3. Algebra

Algebra tests the ability to work with expressions, equations, inequalities and polynomials.

Important topics include:

• Basic algebraic operations
• Simple factors
• Remainder theorem
• HCF and LCM of algebraic expressions
• Theory of polynomials
• Quadratic equations
• Relationship between roots and coefficients
• Simultaneous linear equations in two unknowns
• Analytical and graphical solutions
• Simultaneous linear inequalities in two variables
• Practical problems involving equations and inequalities
• Set language and set notation
• Rational expressions
• Conditional identities
• Laws of indices

Practise solving equations step by step and revise the relevant identities before attempting advanced questions.

4. Trigonometry

Trigonometry focuses on trigonometric ratios, identities and their applications.

Important topics include:

• Sine, cosine and tangent
• Standard trigonometric values
• Trigonometric identities
• Trigonometric tables
• Simple problems on heights and distances

Candidates should memorise standard values and practise applying identities rather than learning formulas without understanding them.

5. Geometry

Geometry includes lines, angles and plane figures, along with their properties and theorems.

Important topics include:

• Lines and angles
• Plane figures
• Angles at a point
• Parallel lines
• Sides and angles of triangles
• Congruence of triangles
• Similarity of triangles
• Concurrence of medians and altitudes
• Properties of parallelograms
• Properties of rectangles and squares
• Circles and their properties
• Tangents and normals to circles
• Loci

Candidates should understand theorems and practise diagram-based problems. Regular revision of geometric properties can help reduce errors.

6. Mensuration

Mensuration covers the calculation of areas, surface areas and volumes of common geometrical figures.

Important topics include:

• Areas of squares and rectangles
• Areas of parallelograms and triangles
• Area of a circle
• Areas of composite figures
• Surface area and volume of cuboids
• Lateral surface area and volume of right circular cones
• Surface area and volume of cylinders
• Surface area and volume of spheres

Learn the relevant formulas and practise questions involving different units and combinations of shapes.

7. Statistics

Statistics covers the interpretation and analysis of basic numerical data.

Important topics include:

• Collection and tabulation of statistical data
• Graphical representation of data
• Histograms
• Frequency polygons
• Bar charts
• Pie charts
• Measures of central tendency

Candidates should practise reading graphs and calculating statistical values accurately.

CDS 1 2027 Marking Scheme

The CDS written examination uses negative marking for incorrect answers. Under the established examination scheme, one-third of the marks assigned to a question are deducted for an incorrect answer.

English and General Knowledge generally contain 120 questions each for 100 marks per paper, while Elementary Mathematics generally contains 100 questions for 100 marks.

Candidates should verify the marking instructions in the official CDS 1 2027 notification before the examination.

How to Prepare for CDS 1 2027

A well-organised preparation strategy can help candidates cover the syllabus without neglecting revision or mock tests.

Step 1: Understand the syllabus. Separate the topics into English, General Knowledge and Mathematics. OTA aspirants can focus on the two required papers.

Step 2: Assess your current level. Solve a previous-year paper to identify strong and weak areas before finalising your timetable.

Step 3: Set daily targets. Allocate time for English practice, GK revision and Mathematics, depending on the academy and your current level.

Step 4: Solve previous-year papers. These papers help you become familiar with the question format, difficulty and time constraints.

Step 5: Take mock tests. Practise under timed conditions and review every incorrect answer to understand the reason behind the mistake.

Step 6: Revise consistently. Reserve time each week for formulas, grammar rules, current affairs and important GK facts.

Step 7: Prepare for the SSB interview. Develop communication, reasoning, teamwork and self-awareness alongside written examination preparation.

Download CDS Previous-Year Question Papers

Previous-year question papers can help candidates understand the level of the CDS examination and practise under realistic time constraints.

Candidates should use previous papers to identify frequently tested concepts, measure their accuracy and improve time management. After each paper, review incorrect answers and revise the relevant topics.

UPSC publishes examination-related resources, including question papers, through its official website. Candidates can visit the UPSC website to look for available CDS question papers and the latest examination information.

Prepare for CDS with Major Kalshi Classes

Major Kalshi Classes has been supporting defence aspirants since 2008, with its offline coaching centre in Prayagraj, Uttar Pradesh. The institute provides preparation resources for CDS and other defence examinations.

Candidates preparing for CDS 1 2027 can explore available MKC programmes and learning resources. Depending on the course, resources may include live or recorded classes, mock tests, assessments, e-notes and study material.

Before enrolling, confirm the current course format, fees, batch schedule and availability of faculty support through the official MKC website.