Section C (3-Mark)

Important Questions for the 2026 CBSE Board Exam

Chapter 1: Chemical Reactions and Equations

6 Questions
1.
Balanced Equations: What is a balanced chemical equation? Why is it necessary to balance chemical equations?
2.
Decomposition Types: Provide one chemical equation each for decomposition reactions triggered by heat, light, and electricity.
3.
Displacement vs. Double Displacement: Define both and explain the primary difference between them with equations.
4.
Corrosion: What is corrosion? Explain the process and state the practical methods to prevent it.
5.
Redox Reactions: Define Oxidation and Reduction reactions with suitable examples.
6.
Thermal Energy: What are exothermic and endothermic reactions? Provide an example for each.

Chapter 3: Metals and Non-metals

7 Questions
1.
Electrolytic Refining: Describe the process of electrolytic refining of Copper with a neat, labeled diagram.
2.
Comparison of Elements: Provide six points of difference (physical or chemical) between metallic and non-metallic elements.
3.
NaCl Formation: Explain the formation of the Sodium Chloride (NaCl) molecule through the transfer of electrons.
4.
Formation: Illustrate the formation of Magnesium Chloride (MgCl₂) by showing the transfer of electrons.
5.
Terminology: Define the following terms: (a) Mineral, (b) Ore, and (c) Gangue.
6.
Corrosion Prevention: Explain the different methods used to prevent the corrosion of metals (Galvanization, Painting, etc.).
7.
Jeweler Application: A jeweler uses 22-carat gold but charges for 24-carat. (a) Why can't we use 24-carat for jewelry? (b) Name two metals added to gold. (c) Which trait of the jeweler is seen here?

Chapter 6: Control and Coordination

6 Questions
1.
Emergency Hormone: Which hormone is secreted during "fight or flight" situations? State its effects on the animal body.
2.
Neuron Structure: Draw a labeled diagram of a neuron (nerve cell) and write a description of its parts.
3.
Action Comparison: How are involuntary actions and reflex actions different from each other?
4.
The Brain: Name the three main parts of the human brain and explain the specific function of each.
5.
Reflex Action: What is a reflex action? Provide a suitable example.
6.
Brain Diagram: Draw a labeled diagram of the human brain and name its parts accurately.

Chapter 7: How do Organisms Reproduce?

7 Questions
1.
Asexual Types: Define asexual reproduction. Explain Budding and Spore Formation with diagrams.
2.
Female System: Draw a labeled diagram of the human female reproductive system and describe its structure.
3.
Flowering Plants: Explain sexual reproduction in flowering plants, including the processes of pollination and fertilization.
4.
Contraception: Briefly describe three different methods used to avoid pregnancy (Mechanical, Chemical, and Surgical).
5.
Regeneration: Explain the process of regeneration in Planaria with the help of a labeled diagram.
6.
Puberty: What is puberty? State the physical and sexual changes observed in both boys and girls during this stage.
7.
Reproduction Comparison: How is sexual reproduction different from asexual reproduction? State the limitations of asexual reproduction.

Chapter 9: Light - Reflection and Refraction

7 Questions
1.
Lens Activity: A student burns paper using a lens in sunlight. Name the lens, state the image position, and draw the ray diagram.
2.
Glass Slab: Describe the refraction of light through a rectangular glass slab with a labeled diagram.
3.
Laws of Refraction: What is refraction of light? State the two Laws of Refraction.
4.
Concave Mirror (Case 1): Draw a ray diagram for an object placed between C and F of a concave mirror. State image nature and size.
5.
Concave Mirror (Case 2): Draw a ray diagram for an object placed at the Center of Curvature (C). Describe the image characteristics.
6.
Mirror Applications: Identify mirrors used in car headlights, rear-view mirrors, and solar furnaces, and give reasons.
7.
Numerical Practice: Practice Examples 9.1–9.4 and Exercise questions 10, 12, 14, 15, and 17.

Chapter 11: Electricity

6 Questions
1.
Parallel Combination: Derive the formula for the equivalent resistance of resistors connected in parallel.
2.
Series Combination: Derive the formula for the equivalent resistance of resistors connected in series.
3.
Heating & Materials: What is the heating effect of current? Why are alloy coils used in toasters/irons instead of pure metals?
4.
Heating Applications: Explain the practical applications of the heating effect of electric current with examples.
5.
Ohm’s Law: State Ohm’s Law, derive its formula, and use it to define the SI unit of resistance (1 Ohm).
6.
Numerical Practice: Practice Examples 11.2, 11.4, 11.6, 11.7, 11.9, 11.11, 11.13 and Exercise questions 9, 12, 13, 15, 16, 17.

Prepared for GSEB Class 10 Science Board Exam 2026 | Section C – 3-Mark Important Questions

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