CBSE Section-wise Answer Book Rule for Class 10 Science and SST

From the 2026 board exams, CBSE changed how Class 10 students write the Science and Social Science papers. Both papers are now split into subject sections, and the answer book has a separate space for each one. Answers written in the wrong section, or mixed across sections, are not evaluated. The board has also said these answers will not be considered later during verification or re-evaluation.

The 2026-27 sample papers keep the same layout, so if you are in Class 10 now, this rule applies to you.

How the two papers are divided

Science (80 marks, 3 hours) has three sections:

• Section A: Biology
• Section B: Chemistry
• Section C: Physics

Social Science (80 marks) has four sections of 20 marks each:

• Section A: History
• Section B: Geography
• Section C: Political Science
• Section D: Economics

Which Science chapters go in which section

The question paper prints the section heading, and that heading is what counts. Still, knowing the split helps you plan your time:

• Biology: Life Processes; Control and Coordination; How do Organisms Reproduce?; Heredity; Our Environment.
• Chemistry: Chemical Reactions and Equations; Acids, Bases and Salts; Metals and Non-metals; Carbon and its Compounds.
• Physics: Light, Reflection and Refraction; The Human Eye and the Colourful World; Electricity; Magnetic Effects of Electric Current.

Where students can slip up

The rule sounds easy until you are 90 minutes into the paper. These are the situations where it goes wrong:

• Skipping a hard question and coming back later. Students write the answer wherever there is space at the end of the book, which is now inside a different section. Leave enough space in the right section before you move on.
• Running out of space in one section. Do not continue the answer in the next section. Ask the invigilator what to do before writing anything outside the section.
• Case-based questions that feel like another subject. A Chemistry case that mentions the human body is still a Chemistry question. Follow the section the question is printed in, not the topic it seems to be about.
• Question numbering. Write the question number exactly as printed. In a section-wise book, a wrong number makes it much harder for the examiner to match your answer.

How to practise for it

• Write every mock and pre-board in a section-wise answer sheet. Draw the section lines yourself at home if you have to. CBSE has asked schools to follow the format in pre-boards too.
• Decide your order in advance. Many students start with the section they are strongest in. That is fine, as long as each answer stays in its own section.
• Keep a rough time split. In Social Science, the four sections carry equal marks, so roughly 40 minutes each, with 20 minutes left to review, is a fair starting point.
• After every mock, check one thing separately: did any answer end up in the wrong section? It takes a minute and builds the habit.

If you want your mocks checked the same way a board examiner would check them, Gradehunt's CBSE Class 10 test series has your handwritten answers checked section by section, with step-wise marks and comments.

For real papers to practise on, use our solved CBSE Class 10 Science and Social Science past papers.