CBSE 10th Science Assertion and Reason Questions: In CBSE Class 10 Science, Assertion and Reason questions have become an important part of the board exam. These questions focus more on understanding and application rather than just memorising facts. They test how well students understand concepts, how they apply them, and how they use logical reasoning. Instead of simply remembering information, students must decide whether the given Assertion is correct and if the Reason properly explains it. This type of question helps students think deeply, analyse ideas, and improve problem-solving skills. Regular practice of such questions increases accuracy, speed, and confidence. It also helps in preparing for competitive exams like JEE and NEET, where similar application-based questions are asked. In this article, we have shared CBSE Class 10 Science Assertion and Reason Questions with Answers to help students prepare well and score higher in their exams.
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What are CBSE Class 10 Science Assertion and Reason Questions?
CBSE Class 10 Science Assertion and Reason questions go beyond simple textbook learning and memorisation. They are meant to check how well students understand concepts, think critically, and apply their knowledge. These questions are now an important part of the exam pattern. They test not only what students know, but also how well they can connect ideas and use logical reasoning to explain them.
Class 10 Science Assertion and Reason questions are designed to test a student’s ability to:
- Apply biological concepts, processes, and principles to explain given statements.
- Evaluate whether the given Reason correctly explains the Assertion.
- Analyse relationships between concepts rather than simply recalling facts.
- Use critical thinking and logical reasoning to determine the truth or falsity of both statements.
Also Check
| CBSE Class 10 Maths Exam Pattern 2025; Check Latest Paper Format and Marking Scheme |
| CBSE Class 10 Maths Syllabus 2025-26 Released; Check Latest Unit-wise Weightage, Download PDF |
CBSE Class 10 Science Assertion and Reason Question Format
According to the CBSE Class 10 Science Paper Pattern 2026, the paper includes:
- 4 Assertion and Reason-based questions, carrying 1 mark each.
- 2 Questions in Section A and 1-1 question in each Section B and C of the question paper
- In Assertion & Reason questions, there are two statements given:
Assertion (A): A statement presented as a fact. It may be true or false.
Reason (R): A supporting statement which may or may not correctly explain the Assertion. It can also be true or false.
Mainly, the students need to identify:
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, and R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
These questions require students to understand the given case, extract relevant information, and solve accordingly.
Tips to Solve Science Assertion and Reason Questions Effectively
To solve CBSE Class 10 Science Assertion and Reason questions effectively, first read the question carefully and understand both statements. Break it into smaller parts and check the Assertion and Reason separately to see if each one is true or false, and whether the Reason correctly explains the Assertion. Practising similar questions regularly helps improve speed and accuracy. Here are some expert tips for solving Class 10 Science Assertion and Reason questions effectively:
1. Read Both Statements Carefully: Understand the meaning of the Assertion and the Reason separately before comparing them.
2. Check the Truth of Each Statement: First, decide if the Assertion is true or false, then check the Reason independently.
3. Find the Relationship: If both are true, see whether the Reason correctly explains the Assertion (cause-and-effect).
4. Eliminate Wrong Options: If confused, rule out obviously incorrect choices to narrow down the answer.
5. Practice from Sample Papers and Past Year Papers: Use the CBSE Sample Paper 2025 and previous years’ board papers to practice similar case-based questions.
CBSE Class 10 Science Assertion and Reason Question
Let’s look at an example to understand how these questions appear:
Two statements are given- one labelled Assertion (A) and the other labelled Reason (R). Which of the following options is correct for the given statements?
Q. No.1: Assertion (A): A rainbow is always formed in a direction opposite to that of the Sun.
Reason (R): White light is composed of seven colors.
A. Both A and R are true, and R is correct explanation of the assertion.
B. Both A and R are true, but R is not the correct explanation of the assertion.
C. A is true, but R is false.
D. A is false, but R is true.
Answer: B. Both A and R are true, but R is not the correct explanation of the assertion.
Q. No.2: Assertion (A): Addition of water to a drum containing calcium oxide makes the drum hot if touched from outside.
Reason (R): Reaction between calcium oxide and water is an endothermic reaction.
A. Both A and R are true, and R is the correct explanation of the assertion.
B. Both A and R are true, and R is not the correct explanation of the assertion.
C. A is true, but R is false.
D. A is false, but R is true.
Answer: C. A is true, but R is false.
Q. No.3: Assertion (A): An incident light ray is passing through the centre of curvature of a concave mirror. After reflection, it retraces its path.
Reason (R): Angle of incidence = Angle of reflection = 0∘
A. Both A and R are true, and R is the correct explanation of the assertion.
B. Both A and R are true, but R is not the correct explanation of the assertion.
C. A is true, but R is false.
D. A is false, but R is true.
Answer: A. Both A and R are true, and R is the correct explanation of the assertion.
Q. No. 4: Assertion (A): Metallic oxides react with acids to form salt and water.
Reason (R): Metallic oxides are basic oxides.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true, but R is false.
D. A is false, but R is true.
Answer: A. Both A and R are true, and R is the correct explanation of the assertion.
Q. No. 5: Assertion (A): The melting point of NaCl is high.
Reason (R): Ionic compounds have a strong electrostatic force of attraction.
A. Both A and R are true, and R is the correct explanation of the assertion.
B. Both A and R are true, and R is not the correct explanation of the assertion.
C. A is true, but R is false.
D. A is false, but R is true.
Answer: A. Both A and R are true, and R is the correct explanation of the assertion.
Q. No. 6: Assertion (A): Translocation of food takes place across the phloem.
Reason (R): Phloem is a vascular tissue that has a flow of materials in upward direction only.
A. Both A and R are true, and R is the correct explanation of the assertion.
B. Both A and R are true, and R is not the correct explanation of the assertion.
C. A is true, but R is false.
D. A is false, but R is true.
Answer: C. A is true, but R is false.
Q. No. 7: Assertion (A): All arteries carry oxygenated blood from the heart to various organs of the body.
Reason (R): Pulmonary vein carries oxygenated blood to the heart.
A. Both A and R are true, and R is the correct explanation of the assertion.
B. Both A and R are true, and R is not the correct explanation of the assertion.
C. A is true, but R is false.
D. A is false, but R is true.
Answer: D. A is false, but R is true.
Q. No. 8: Assertion (A): There is no digestion of proteins in the mouth.
Reason (R): Saliva contains salivary amylase.
A. Both A and R are true, and R is the correct explanation of the assertion.
B. Both A and R are true, and R is not the correct explanation of the assertion.
C. A is true, but R is false.
D. A is false, but R is true.
Answer: B. Both A and R are true, and R is not the correct explanation of the assertion.
Q. No. 9: Assertion (A): Kidney produces the urine by the process of ultrafiltration.
Reason (R): Urine is stored in the urinary bladder.
A. Both A and R are true, and R is the correct explanation of the assertion.
B. Both A and R are true, and R is not the correct explanation of the assertion.
C. A is true, but R is false.
D. A is false, but R is true.
Answer: B. Both A and R are true, and R is not the correct explanation of the assertion.
Q. No. 10: Assertion (A): Water in the deep sea appears blue.
Reason (R): The scattering of the blue component of the white sunlight by tiny molecules is responsible for blue appearance of ocean.
A. Both A and R are true, and R is correct explanation of the assertion.
B. Both A and R are true, but R is not the correct explanation of the assertion.
C. A is true, but R is false.
D. A is false, but R is true.
Answer: A. Both A and R are true, and R is correct explanation of the assertion.
CBSE Class 10 Science Assertion and Reason Question PDF [Free]
Click on the link provided below to download the CBSE Class 10 Science Assertion and Reason Question PDF with answers for free without any login. Get the direct link to download the PDF.
| CBSE Class 10 Science Assertion and Reason Question PDF | Download here |
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Common Mistakes to Avoid In Science Assertion and Reason Questions
Many students lose marks in Science Assertion and Reason questions because of small but avoidable mistakes. Knowing these mistakes in advance can help you approach such questions with more confidence and accuracy.
- Not reading both statements carefully: Skipping keywords like “always,” “never,” or “only” can change the meaning of the question.
- Assuming the Reason is correct without checking: Always verify both statements independently first.
- Confusing correlation with cause: Just because both statements are true doesn’t mean the Reason explains the Assertion.
- Relying on memorisation only: These questions test understanding; revise concepts and applications instead of rote learning.
- Not practising enough: Lack of practice with previous year and sample papers reduces speed and accuracy.
- Lack of practice: These questions are relatively new, and many students aren’t used to them yet.
CBSE Class 10 Science Syllabus 2025-26
The Central Board of Secondary Education (CBSE) has released the Science Syllabus for Class 10 for the 2025-26 academic year. This Science Syllabus outlines the course structure, chapters, and topics that students will need to study in the subject. The CBSE Class 10 Science syllabus covers a wide range of topics, including Number Systems, Algebra, Coordinate Geometry, Geometry, Trigonometry, Mensuration and Statistics & Probability. It is divided into units with specific weightage, helping students plan their preparation effectively. The Class 10th Science unite-wise chapters and weightage are provided below :
| Unit Name | Chapter Name |
Weightage in Marks |
|
Chemical Substances-Nature and Behaviour |
Chemical Reactions and Equations |
25 |
| Acids, Bases and Salts | ||
| Metals and Non-metals | ||
| Carbon and its Compounds | ||
|
World of Living |
Life processes |
25 |
| Control and co-ordination in animals and plants | ||
| Reproduction | ||
| Heredity and Evolution | ||
| Natural Phenomena | Natural Phenomena | 12 |
|
Effects of Current |
Effects of Current |
13 |
| Magnetic effects of current | ||
| Natural Resources | Our environment | 5 |
Check the latest and detailed CBSE Class 10 Science Syllabus 2025-26; Check Latest Unit-wise Weightage, Download PDF.
CBSE Class 10 Science Exam Pattern 2025-26
CBSE has released the exam pattern and marking scheme for the 2025-26 academic year. Based on the official question paper design shared along with the syllabus, the board will follow the same exam pattern and marking scheme as in 2024-25. The CBSE Class 12 Science board exam for 2025–26 consists of a theory paper of 80 marks and the remaining 20 marks for the practical exam. The question paper will be divided into three sections- Section A (Biology), Section B (Chemistry) and Section C (Physics):
| Section | Question Type | Number of Questions | Marks |
| A |
|
16 | 30 |
| B |
|
13 | 25 |
| C |
|
10 | 25 |
| Total | 39 | 80 | |
Check the latest and detailed CBSE Class 10th Science Exam Pattern 2025-26 with Marking Scheme.