CBSE Class 10 Science Question Bank 2026–27: MCQs with Answers

Preparing for the Science board examination requires more than reading chapters and memorising definitions, formulas and scientific terms. Questions may ask you to apply concepts, interpret situations and distinguish between similar options. Without enough practice, it can be difficult to identify weak areas, manage time and avoid mistakes while solving objective questions.

The CBSE Class 10 Science Question Bank 2026–27 provides practice questions with answers to support your revision across important Science topics. You can use these questions to test your understanding, practise different MCQ formats, review incorrect answers and revisit concepts that require more attention. Regular practice can help you improve accuracy and become more familiar with objective-type questions.

What Does the CBSE Class 10 Science Question Bank 2026–27 Cover?

The questions cover concepts from different areas of Class 10 Science, including chemical reactions, acids and bases, carbon compounds, ecosystems and trophic levels. The topics below indicate the areas covered in the given question set.

CBSE Class 10 Science Important MCQs with Answers

Practising MCQs after revising a concept can help you check your understanding and recognise areas where you need more practice. The following questions cover important concepts from different Class 10 Science topics.

Question 1

The substance not likely to contain CaCO₃ is:

a) Dolomite
b) A marble statue
c) Calcined gypsum
d) Sea shells

Answer: c) Calcined gypsum

Question 2

Gas A (CO₂), obtained by heating calcium carbonate, is a reactant for a very important biochemical process which occurs in the presence of sunlight. Identify the name of the process:

a) Respiration
b) Photosynthesis
c) Transpiration
d) Photolysis

Answer: b) Photosynthesis

Question 3

Calcium oxide can be reduced to calcium by heating with sodium metal. Which compound would act as an oxidising agent in the above process?

a) Sodium
b) Sodium oxide
c) Calcium
d) Calcium oxide

Answer: d) Calcium oxide

Question 4

Chlorine gas reacts with __________ to form bleaching powder:

a) Dry Ca(OH)₂
b) Dilute solution of Ca(OH)₂
c) Concentrated solution of Ca(OH)₂
d) Dry CaO

Answer: a) Dry Ca(OH)₂

Question 5

What will happen if we take dry HCl gas instead of an aqueous solution of HCl during its reaction with MnO₂?

a) Reaction will occur faster
b) Reaction will not occur
c) Reaction rate will be slow
d) Reaction rate will remain the same

Answer: b) Reaction will not occur

Question 6

Identify the types of chemical reaction occurring during the complete combustion of fuel:

a) Oxidation and endothermic reaction
b) Decomposition and exothermic reaction
c) Oxidation and exothermic reaction
d) Combination and endothermic reaction

Answer: c) Oxidation and exothermic reaction

Question 7

A student while walking on the road observed that a cloud of black smoke belched out from the exhaust stack of moving trucks. Choose the correct reason for the production of black smoke:

a) Limited supply of air leads to incomplete combustion of fuel.
b) Rich supply of air leads to complete combustion of fuel.
c) Rich supply of air leads to a combination reaction.
d) Limited supply of air leads to complete combustion of fuel.

Answer: a) Limited supply of air leads to incomplete combustion of fuel.

Question 8

Although nitrogen is the most abundant gas in the atmosphere, it does not take part in combustion. Identify the correct reason for this statement:

a) Nitrogen is a reactive gas
b) Nitrogen is an inert gas
c) Nitrogen is an explosive gas
d) Only hydrocarbons can take part in combustion

Answer: b) Nitrogen is an inert gas

Question 9

Predict the pH value of the water of river Yamuna if the reason for froth is a high content of detergents dissolved in it:

a) 10–11
b) 5–7
c) 2–5
d) 7

Answer: a) 10–11

Question 10

Which of the following statements is correct for water with detergents dissolved in it?

a) Low concentration of hydroxide ion (OH⁻) and high concentration of hydronium ion (H₃O⁺)
b) High concentration of hydroxide ion (OH⁻) and low concentration of hydronium ion (H₃O⁺)
c) High concentration of hydroxide ion (OH⁻) as well as hydronium ion (H₃O⁺)
d) Equal concentration of both hydroxide ion (OH⁻) and hydronium ion (H₃O⁺)

Answer: b) High concentration of hydroxide ion (OH⁻) and low concentration of hydronium ion (H₃O⁺)

Question 11

Biogas is a mixture of which of the following gases?

a) Ethane, carbon monoxide, nitrogen and butane
b) Methane, hydrogen, carbon dioxide and nitrogen
c) Butane, carbon monoxide, propane and hydrogen
d) Carbon monoxide, sulphur dioxide and hydrogen

Answer: b) Methane, hydrogen, carbon dioxide and nitrogen

Question 12

If Ravi is consuming curd/yogurt for lunch, which trophic level in a food chain should he be considered as occupying?

a) First trophic level
b) Second trophic level
c) Third trophic level
d) Fourth trophic level

Answer: c) Third trophic level

Question 13

Matter and energy are two fundamental inputs of an ecosystem. Which statement correctly describes their movement?

a) Energy is bidirectional and matter is repeatedly circulating.
b) Energy is repeatedly circulating and matter is unidirectional.
c) Energy is unidirectional and matter is repeatedly circulating.
d) Energy is multidirectional and matter is bidirectional.

Answer: c) Energy is unidirectional and matter is repeatedly circulating.

Question 14

Which of the following limits the number of trophic levels in a food chain?

a) Decrease in energy at higher trophic levels
b) Less availability of food
c) Polluted air
d) Water

Answer: a) Decrease in energy at higher trophic levels

Question 15

Which group of organisms is NOT included in an ecological food chain?

a) Carnivores
b) Saprophytes
c) Herbivores
d) Predators

Answer: b) Saprophytes

CBSE Class 10 Science Question Bank 2026–27 PDF

Understanding the key concepts becomes easier when you have regular access to practice questions and their answers. The CBSE Class 10 Science Question Bank 2026–27 PDF allows you to practise MCQs, check your responses and revisit topics where you need more practice.

How Can the CBSE Class 10 Science Question Bank Help You Prepare?

Using a question bank alongside regular revision can help you turn concept learning into active practice. Solving questions, checking your responses and revisiting difficult topics can make your preparation more focused while helping you recognise the areas that need additional attention.

• Revise concepts through questions: Use MCQs after completing a topic to check how well you remember and apply the concepts.

• Practise independently: Attempt each question before checking the answer to assess your understanding without assistance.

• Identify learning gaps: Review incorrect responses to find concepts that require further explanation or revision.

• Focus on difficult topics: Keep a record of chapters where you make repeated mistakes and give them additional practice.

• Improve question-solving speed: Set a reasonable time limit while practising to become more comfortable with objective questions.

• Review your progress: Compare your performance across practice sessions to identify improvement and areas that still need attention.

Practising the CBSE Class 10 Science Question Bank 2026–27 can help you revise concepts, apply your knowledge through MCQs and identify topics that need more attention. Regular practice, careful review of mistakes and revision of difficult concepts can help you improve accuracy and prepare more effectively for the Science examination.