1569+ CBSE Class 10 Science Assertion and Reason Questions

Are you preparing for your CBSE Class 10 Science examination? If so, it’s crucial to familiarize yourself with different question formats, including the Assertion and Reason questions. This article aims to guide you through the concept of Assertion and Reason questions, provide tips for answering them effectively, and highlight their significance in the CBSE Class 10 Science examination.

An assertion reason type question consists of two statements; an assertion (statement of fact) and a reason. First, you have to determine whether each statement is correct or not and the next step is to determine whether the reason is the correct explanation of the assertion or not.

Chapterwise Assertion Reason Questions for Class 10 Science

Assertion and Reason questions are a unique format that assesses a student’s understanding of scientific concepts and their ability to provide logical explanations. These questions consist of two statements: an assertion and a reason. The student is required to determine the relationship between the two statements and choose the correct option from the given choices.

Guidelines for Answering Assertion and Reason Questions

To answer Assertion and Reason questions accurately, follow these guidelines:

i. Analyze the Assertion and Reason Statements

Carefully read and analyze both the assertion and reason statements. Understand the content and context of each statement and their relationship to each other.

ii. Determine the Correct Option

Based on your analysis, determine the correct option among the choices provided. The options usually include:

  • A. Both the assertion and reason are true, and the reason is the correct explanation of the assertion.
  • B. Both the assertion and reason are true, but the reason is not the correct explanation of the assertion.
  • C. The assertion is true, but the reason is false.
  • D. The assertion is false, but the reason is true.

iii. Eliminate Incorrect Options

Eliminate the incorrect options by carefully evaluating the relationship between the assertion and the reason. Cross out options that contradict your analysis of the statements.

iv. Choose the Most Appropriate Option

Select the most appropriate option among the remaining choices based on your understanding of the assertion and reason statements.

Tips for Answering Assertion and Reason Questions

To excel in answering Assertion and Reason questions, consider the following tips:

  • Read both the assertion and reason statements carefully to understand their context.
  • Pay attention to keywords and phrases that indicate the relationship between the two statements.
  • Avoid making assumptions or bringing outside knowledge that is not mentioned in the statements.
  • Eliminate options that contradict your understanding of the relationship between the assertion and reason.
  • Choose the option that best aligns with your analysis of the statements.

Importance of Assertion and Reason Questions in CBSE Class 10 Science Examination

Assertion and Reason questions hold significant importance in the CBSE Class 10 Science examination. They test a student’s logical reasoning skills and comprehension of scientific principles. By including these questions, the CBSE aims to evaluate a student’s ability to analyze and apply their knowledge to solve complex problems. It also encourages students to think critically and develop a deeper understanding of the subject.

Class 10 Science Syllabus

Theory Marks – 80Career Counseling

Unit No.UnitMarks
IChemical Substances-Nature and Behaviour25
IIWorld of Living25
IIINatural Phenomena12
IVEffects of Current13
VNatural Resources05
 Internal assessment20
 Grand Total100
Theme: Materials
Unit 1: Chemical Substances – Nature and Behaviour
Chemical reactions: Chemical equation, Balanced chemical equation, implications of a balanced chemical equation, types of chemical reactions: combination, decomposition, displacement, double displacement, precipitation, endothermic exothermic reactions, oxidation, and reduction.
Acids, bases, and salts: Their definitions in terms of furnishing of H+ and OH ions, General properties, examples and uses, neutralization, concept of pH scale (Definition relating to logarithm not required), importance of pH in everyday life; preparation and uses of Sodium Hydroxide, Bleaching powder, Baking soda, Washing soda and Plaster of Paris.
Metals and nonmetals: Properties of metals and non-metals; Reactivity series; Formation and properties of ionic compounds; Basic metallurgical processes; Corrosion and its prevention.
Carbon compounds: Covalent bonding in carbon compounds. Versatile nature of carbon. Homologous series. Nomenclature of carbon compounds containing functional groups (halogens, alcohol, ketones, aldehydes, alkanes, and alkynes), difference between saturated hydrocarbons and unsaturated hydrocarbons. Chemical properties of carbon compounds (combustion, oxidation, addition, and substitution reaction). Ethanol and Ethanoic acid (only properties and uses), soaps, and detergents.
Theme: The World of the Living
Unit 2: World of Living
Life processes: ‘Living Being’. Basic concept of nutrition, respiration, transport and excretion in plants and animals.
Control and co-ordination in animals and plants: Tropic movements in plants; Introduction of plant hormones; Control and co-ordination in animals: Nervous system; Voluntary, involuntary and reflex action; Chemical co-ordination: animal hormones.
Reproduction: Reproduction in animals and plants (asexual and sexual) reproductive health – need and methods of family planning. Safe sex vs HIV/AIDS. Child bearing and women’s health.
Heredity and Evolution: Heredity; Mendel’s contribution- Laws for inheritance of traits: Sex determination: brief introduction: (topics excluded – evolution; evolution and classification and evolution should not be equated with progress).
Theme: Natural Phenomena
Unit 3: Natural Phenomena
Reflection of light by curved surfaces; Images formed by spherical mirrors, centre of curvature, principal axis, principal focus, focal length, mirror formula (Derivation not required),magnification.
Refraction; Laws of refraction, refractive index. Refraction of light by spherical lens; Image formed by spherical lenses; Lens formula(Derivation not required); Magnification. Power of a lens.
Human eye: Functioning of a lens in human eye, defects of vision and their corrections, applications of spherical mirrors and lenses.
Refraction of light through a prism, dispersion of light, scattering of light, applications in dailylife (excluding colour of the sun at sunrise and sunset).
Theme: How Things Work
Unit 4: Effects of Current
Electricity: Electric current, potential difference and electric current. Ohm’s law; Resistance, Resistivity, Factors on which the resistance of a conductor depends. Series combination of resistors, parallel combination of resistors and its applications in daily life. Heating effect of electric current and its applications in daily life. Electric power, Interrelation between P, V, I and R.
Magnetic effects of current: Magnetic field, field lines, field due to a current carryingconductor, field due to current carrying coil or solenoid; Force on current carrying conductor, Fleming’s Left Hand Rule, Direct current. Alternating current: frequency of AC. Advantage of AC over DC. Domestic electric circuits.
Theme: Natural Resources
Unit 5: Natural Resources
Our environment: Eco-system, Environmental problems, Ozone depletion, waste production and their solutions. Biodegradable and non-biodegradable substances.
Practical should be conducted alongside the concepts taught in theory classes. This will enable you to grasp the concepts better.


Understanding and effectively answering Assertion and Reason questions is crucial for scoring well in the CBSE Class 10 Science examination. By following the guidelines and tips provided in this article, you can enhance your preparation and confidently approach these questions. Remember to practice regularly and analyze the relationship between the assertion and reason statements to excel in this question format.


Are Assertion and Reason questions only limited to CBSE Class 10 Science?

Assertion and Reason questions can be found in various science examinations, including CBSE Class 10 Science, CBSE Class 12 Science, and competitive entrance exams.

Can both the assertion and reason statements be false?

No, in Assertion and Reason questions, both statements cannot be false.

How should I approach Assertion and Reason questions if I’m unsure about the correct option?

Eliminate the options that contradict your understanding of the assertion and reason statements. If you’re still unsure, make an informed guess based on your analysis.

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