CBSE Class 12 Most Repeated Questions 2027: Subject-Wise Analysis for Science, Commerce, and Arts

In short: CBSE Class 12 board exams follow strong patterns. Certain derivations, theorems, and question types appear year after year. A 10-year analysis reveals that topics like Biot-Savart law, electrochemistry numericals, and integration by parts have been asked 8 or more times out of 10. Knowing these patterns gives you a clear advantage in prioritizing your revision.

CBSE board exams are not random. If you sit down with 10 years of previous year papers and mark every question that repeats, you will find a clear pattern. Certain derivations come back almost every year. Certain types of numericals rotate between just two or three variations. And some theory questions appear so consistently that skipping them would be a mistake.

This guide breaks down the most repeated questions in CBSE Class 12 across Science, Commerce, and Arts streams based on analysis of papers from 2015 to 2025.

Why Repeated Questions Matter

CBSE designs papers using a blueprint that allocates specific marks to each unit. Within those units, some topics are more "exam-friendly" than others. They are conceptually rich, easy to frame questions around, and align well with the marking scheme. That is why certain questions keep coming back.

Studying repeated questions does not mean ignoring the rest of the syllabus. It means knowing where to invest your heaviest revision time. If a topic has appeared 8 out of 10 years, it deserves more practice than a topic that appeared once.

For a complete exam strategy, see our CBSE Class 12 board exam complete strategy guide.

Physics - Most Repeated Questions

Physics is the most predictable subject in the Science stream. Derivations and numericals follow a tight cycle.

Electrostatics and Current Electricity (16 marks)

Derivation of electric field due to a dipole on axial and equatorial positions - asked 9 out of 10 years
Gauss's theorem and its application to find the electric field due to a uniformly charged sphere or infinite plane sheet - asked 8 out of 10 years
Numericals on Wheatstone bridge and meter bridge - asked 7 out of 10 years
Kirchhoff's rules and their application to simple circuits - asked 7 out of 10 years
Capacitance of a parallel plate capacitor with and without dielectric - asked 6 out of 10 years

Magnetic Effects and Electromagnetic Induction (16 marks)

Biot-Savart law derivation and its application to find the magnetic field at the centre of a circular loop - asked 8 out of 10 years
Ampere's circuital law and magnetic field due to a solenoid - asked 7 out of 10 years
Working principle of a moving coil galvanometer, its conversion to ammeter and voltmeter - asked 8 out of 10 years
Self-inductance and mutual inductance derivations - asked 6 out of 10 years
AC generator working and principle - asked 7 out of 10 years

Optics (14 marks)

Ray diagram and derivation for image formation by a lens using the lens maker's formula - asked 8 out of 10 years
Young's double slit experiment derivation for fringe width - asked 9 out of 10 years
Resolving power of a microscope or telescope - asked 5 out of 10 years
Total internal reflection and its applications - asked 6 out of 10 years

Modern Physics (10 marks)

Einstein's photoelectric equation and explanation of experimental observations - asked 8 out of 10 years
Bohr's model of hydrogen atom, derivation of radius and energy of nth orbit - asked 7 out of 10 years
Nuclear binding energy curve and its implications - asked 5 out of 10 years
Radioactive decay law derivation - asked 6 out of 10 years

For a full list of derivations, check our CBSE Class 12 Physics derivations list.

Chemistry - Most Repeated Questions

Chemistry has three sections: Physical, Organic, and Inorganic. Each section has its own set of high-frequency questions.

Physical Chemistry (23 marks)

Numericals on electrochemical cells (Nernst equation, EMF calculation) - asked 9 out of 10 years
Raoult's law derivation and colligative properties numericals - asked 8 out of 10 years
Rate law, order of reaction, and integrated rate equations - asked 8 out of 10 years
Kohlrausch's law and its applications - asked 6 out of 10 years

Organic Chemistry (19 marks)

Name reactions: Cannizzaro, Aldol condensation, Kolbe's, Williamson synthesis - at least 2 to 3 asked every year
Distinguish between pairs of compounds using chemical tests - asked 8 out of 10 years
Conversion reactions (converting one organic compound to another in 2 to 3 steps) - asked 9 out of 10 years
SN1 vs SN2 mechanism comparison - asked 7 out of 10 years
Questions on amines: basicity order, Hoffmann bromamide reaction - asked 7 out of 10 years

Inorganic Chemistry (16 marks)

Lanthanoid contraction causes and consequences - asked 7 out of 10 years
Contact process or Ostwald process - asked 6 out of 10 years
Crystal field theory and colour of coordination compounds - asked 6 out of 10 years
Reasons for anomalous behaviour of first element in each group - asked 5 out of 10 years

Mathematics - Most Repeated Questions

Maths papers have a well-defined structure and certain problem types rotate every year.

Calculus (35 marks - largest section)

Integration by parts and partial fractions - asked 9 out of 10 years
Definite integrals using properties of definite integrals - asked 8 out of 10 years
Area under curves (parabola, circle, ellipse bounded regions) - asked 9 out of 10 years
Differential equations: forming and solving linear differential equations - asked 8 out of 10 years
Continuity and differentiability of piecewise functions - asked 7 out of 10 years
Maxima and minima word problems - asked 8 out of 10 years

Algebra (13 marks)

Properties of determinants and solving system of equations using Cramer's rule or inverse matrix - asked 9 out of 10 years
Proving properties of determinants using row/column operations - asked 7 out of 10 years
Symmetric and skew-symmetric matrix problems - asked 5 out of 10 years

Vectors and 3D Geometry (14 marks)

Shortest distance between two skew lines - asked 8 out of 10 years
Equation of a plane in different forms and distance of a point from a plane - asked 8 out of 10 years
Scalar triple product and its applications - asked 6 out of 10 years

Probability (8 marks)

Bayes' theorem application problems - asked 9 out of 10 years
Probability distribution and finding mean and variance - asked 7 out of 10 years

Learn how to approach these problems using the right techniques in our guide on science-backed study techniques for students.

Biology - Most Repeated Questions

Biology is more theory-heavy, but specific diagrams and processes appear with high frequency.

Reproduction (14 marks)

Draw and label the sectional view of a human ovary or seminiferous tubule - asked 8 out of 10 years
Process of fertilization and implantation in humans - asked 7 out of 10 years
Development of male and female gametophytes in angiosperms - asked 8 out of 10 years

Genetics and Evolution (18 marks)

Explain Mendel's law of independent assortment with a dihybrid cross - asked 9 out of 10 years
Describe the process of transcription in prokaryotes - asked 7 out of 10 years
Explain the Human Genome Project and its goals - asked 5 out of 10 years
Hardy-Weinberg principle and factors affecting genetic equilibrium - asked 6 out of 10 years

Biology and Human Welfare (14 marks)

Steps in recombinant DNA technology - asked 7 out of 10 years
Applications of biotechnology in health (gene therapy, molecular diagnostics) - asked 6 out of 10 years
Types of immunity with examples - asked 7 out of 10 years
Life cycle of Plasmodium - asked 5 out of 10 years

Ecology (14 marks)

Draw and explain an ecological pyramid - asked 6 out of 10 years
Succession: primary and secondary with examples - asked 5 out of 10 years
Biodiversity: types, importance, and conservation strategies - asked 7 out of 10 years

Commerce Stream - Key Repeated Questions

Accountancy

Preparation of partners' capital accounts (fixed and fluctuating) - asked almost every year
Treatment of goodwill on admission, retirement, and death of a partner - asked every year
Cash flow statement preparation - asked 9 out of 10 years
Ratio analysis (current ratio, debt-equity ratio, etc.) - asked 8 out of 10 years
Issue and redemption of debentures - asked 7 out of 10 years

Business Studies

Functions of management (Planning, Organizing, Staffing, Directing, Controlling) - asked every year
Principles of management by Fayol and Taylor - asked 9 out of 10 years
Marketing mix (4Ps) with examples - asked 8 out of 10 years
Financial management: capital structure decisions and factors - asked 7 out of 10 years
Consumer Protection Act provisions - asked 6 out of 10 years

Arts Stream - Key Repeated Questions

English (Common across streams)

Notice writing and formal/informal invitation - format-based, asked every year
Report writing or article writing - asked every year
Letter to the editor or business/official letter - asked 9 out of 10 years
Extract-based questions from prose and poetry - asked every year
Long answer on character analysis or theme discussion - asked every year

History

Analysis of Mughal court and administration through Ain-i-Akbari - asked frequently
Interpretation of archaeological sources and their limitations - asked 7 out of 10 years
Map-based questions on important historical sites - asked every year
Themes related to the Revolt of 1857 - asked 6 out of 10 years

Political Science

Challenges to and the restoration of the Indian Constitution during the Emergency - asked frequently
India's foreign policy: Non-Aligned Movement and its relevance - asked 6 out of 10 years
Rise of regional parties and coalition politics - asked 7 out of 10 years

How to Use This Analysis Effectively

Knowing which questions repeat is only the first step. Here is how to turn this knowledge into marks:

Step 1: Cross-reference with NCERT

Every repeated question traces back to NCERT content. Read the relevant NCERT sections carefully and practice the end-of-chapter questions. Learn how to read NCERT effectively.

Step 2: Solve Previous Year Papers

Solve at least 8 to 10 previous year papers per subject. Do not just read the questions. Write full answers under timed conditions. Check our guide on how to use previous year question papers.

Step 3: Build a High-Priority Question Bank

Make a separate notebook or document for questions that appear 6 or more times out of 10 years. These are your non-negotiable revision topics. Revise them weekly.

Step 4: Practice the Exact Format

Board examiners follow a marking scheme. Learn how marks are allocated for each step. A derivation that skips a step loses marks even if the final answer is correct. Read our guide on how to write answers that score maximum marks.

Step 5: Do Not Ignore Low-Frequency Topics

Some questions appear only once or twice in 10 years. Do not skip them entirely. Cover them at a basic level so you are not caught off guard. But allocate less time to them compared to high-frequency topics.

Frequently Asked Questions

Does CBSE actually repeat the same questions in Class 12 board exams?

CBSE does not copy-paste questions from previous years. But the underlying concepts, derivation types, and problem structures repeat consistently. For example, the Biot-Savart law derivation has been asked in some form 8 out of the last 10 years. The wording changes, but the core requirement stays the same.

Which Class 12 subject has the most predictable question pattern?

Physics and Mathematics are the most predictable for the Science stream. In Physics, derivations rotate from a small pool of about 15 to 20 core derivations. In Maths, integration and probability problems follow a clear pattern. For Commerce, Accountancy is highly predictable because the question format for partnership accounts and financial statements barely changes.

How many previous year papers should I solve for Class 12?

Aim for 8 to 10 papers per subject. This gives you enough data to spot repeating patterns. After solving 5 papers, you will start recognizing the same question types. Use the remaining papers as timed practice tests.

Should I only focus on repeated questions and skip everything else?

No. Repeated questions should guide your revision priorities, not replace full syllabus coverage. CBSE occasionally introduces new question formats, especially competency-based questions. Cover the full NCERT syllabus first, then use repeated question analysis to decide where to invest extra practice time.

Are repeated questions the same for CBSE sample papers and actual board papers?

There is significant overlap because CBSE sample papers are designed to reflect the actual exam pattern. However, board papers sometimes include slightly different applications of the same concept. Use both sample papers and previous year papers for the most thorough preparation.

Padhaao's Exam Practice mode generates full-length practice papers based on the CBSE blueprint, automatically weighting high-frequency topics. You can also use the Important Questions mode to get a curated list of the most likely questions for each chapter. Three chapters are free every day, covering all Class 12 subjects across Science, Commerce, and Arts.

Start with the most repeated topics, master them, and then expand to cover the rest. That is how you study smart, not just hard.