Class 10 Science
Previous Board Examination – Full Solved Answers (Set 4)
The following answers are written in simple, clear student language as expected by CBSE examiners to award full marks.
Section A – MCQs (Answers)
1. Oxygen
2. Neuron
3. Volt
4. Zinc
5. Virtual and erect
6. WBC
7. Carbon dioxide
8. Potential energy
9. Iris
10. More than 7
Section B – Very Short Answer
11. Define respiration.
Respiration is the process by which food is broken down in the presence or absence of oxygen to release energy.
12. Write the chemical formula of hydrated lime.
The chemical formula of hydrated lime is Ca(OH)₂.
13. What is electric power?
Electric power is the rate at which electrical energy is consumed or work is done in an electric circuit.
14. What is fertilisation?
Fertilisation is the fusion of male and female gametes to form a zygote.
15. Name the hormone that controls metabolism.
The hormone that controls metabolism is Thyroxine.
Section C – Short Answer
16. Explain aerobic respiration.
Aerobic respiration is the process of breaking down glucose in the presence of oxygen to release energy.
- It produces carbon dioxide and water.
- A large amount of energy is released.
17. Write three properties of acids.
- Acids are sour in taste.
- They turn blue litmus red.
- They produce H⁺ ions in aqueous solution.
18. State the laws of refraction of light.
- The incident ray, refracted ray and the normal lie in the same plane.
- The ratio of sine of angle of incidence to sine of angle of refraction is constant.
19. Describe the structure of a nephron.
A nephron is the structural and functional unit of kidney.
- Bowman’s capsule
- Glomerulus
- Renal tubule
It helps in filtration and formation of urine.
(Draw neat labelled diagram of nephron)
20. Explain reflection of light.
Reflection of light is the bouncing back of light rays when they strike a smooth surface like a mirror.
It follows the laws of reflection.
21. What is non-renewable resource? Give examples.
Non-renewable resources are resources that cannot be replenished once exhausted.
Examples: Coal, petroleum, natural gas.
Section D – Long Answer
22. Explain the process of respiration in human beings.
Respiration in humans occurs in the following steps:
- Breathing – inhalation and exhalation
- Oxygen is transported by blood to cells
- Glucose is oxidised to release energy
Carbon dioxide is released as waste.
23. Describe reproduction in flowering plants.
Reproduction in flowering plants involves:
- Pollination
- Fertilisation
- Seed formation
Seeds germinate to form new plants.
24. Derive the formula for electric power.
Electric power is defined as:
P = Work / Time
Since Work = V × Q and Q / t = I,
P = VI
Using V = IR,
P = I²R
25. Explain the defects of vision.
Common defects of vision are:
- Myopia – corrected using concave lens
- Hypermetropia – corrected using convex lens
- Presbyopia – corrected using bifocal lens
(Draw ray diagrams)
Section E – Case Study Based
26.
a) The process is Rusting.
b) Presence of air and moisture.
c) Painting or galvanisation can prevent rusting.
Shaktimatha CBSE Learning
Class 10 Science – Previous Board Exam Full Answers (Set 4)
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