Question 1

Q1. Which of the following reactions is a decomposition reaction?

Accepted Answer

Option B: 2AgCl → 2Ag + Cl ₂. In decomposition reactions, a single compound breaks into simpler substances, often due to heat, light, or electricity.

Question 2

Q2. Which part of the eye controls the amount of light entering it?

Accepted Answer

Option C: Iris. The iris adjusts the size of the pupil to regulate light entering the eye.

Question 3

Q3. Which cell organelle is known as the "powerhouse of the cell"?

Accepted Answer

Option C: Mitochondria. Mitochondria release energy during respiration and store it in the form of ATP.

Question 4

Q4. Which of the following metals is least reactive?

Accepted Answer

Option C: Copper. Copper is less reactive and does not react easily with water or dilute acids.

Question 5

Q5. Which process is responsible for transport of food in plants?

Accepted Answer

Option C: Translocation. Food prepared in leaves is transported through phloem by translocation.

Question 6

Q6. A student dipped an iron nail in copper sulphate solution and observed a colour change after some time. The blue colour faded because:

Accepted Answer

Option B: Iron displaced copper from solution. Iron is more reactive than copper and displaces it from copper sulphate solution.

Question 7

Q7. A heater marked 1000 W operates for 2 hours. The electrical energy consumed is:

Accepted Answer

Option C: 2 kWh. Energy = Power × Time = 1 kW × 2 h = 2 kWh

Question 8

Q8. A potted plant kept near a window bends toward sunlight after a few days. This movement is due to:

Accepted Answer

Option C: Phototropism. Shoots grow toward light due to unequal growth caused by auxin hormone.

Question 9

Q9. Which property makes ionic compounds generally hard and brittle?

Accepted Answer

Option B: Strong electrostatic forces between ions. Strong attraction between oppositely charged ions makes ionic compounds hard and brittle.

Question 10

Q10. The valency of oxygen is:

Accepted Answer

Option B: 2. Oxygen requires two electrons to complete its octet, so its valency is 2.

Question 11

Q11. Seat belts in cars reduce injuries during accidents because they:

Accepted Answer

Option C: Prevent sudden forward motion of passengers. Seat belts counter the effect of inertia and protect passengers during sudden braking.

Question 12

Q12. Assertion (A): Rusting of iron is faster in coastal regions. Reason (R): Coastal air contains more moisture.

Accepted Answer

Option A: Both A and R are true and R is correct explanation of A. Moist air near coastal areas accelerates rusting by providing water needed for corrosion.

Question 13

Q13. Assertion (A): Concave mirrors are used in vehicle headlights. Reason (R): Concave mirrors can produce parallel beams of light when source is placed at focus.

Accepted Answer

Option A: Both A and R are true and R is correct explanation of A. Placing the bulb at focus produces strong parallel beams suitable for headlights.

Question 14

Q14. Case Study: A student tested four solutions using universal indicator. • Solution A → pH 2 • Solution B → pH 7 • Solution C → pH 10 • Solution D → pH 5 Which solution is most basic?

Accepted Answer

Option C: C. Higher pH values indicate stronger basic nature.

Question 15

Q15. Case Study: A student performed an experiment using a concave mirror and observed a real inverted image on a screen. Which condition is definitely true?

Accepted Answer

Option B: Object is beyond focus. Concave mirrors form real inverted images only when object is beyond focus.

Question 16

Q16. A student claims that increasing voltage across a conductor always increases current. Which condition makes this statement incorrect?

Accepted Answer

Option A: Temperature changes significantly. Ohm's law holds only when temperature and physical conditions remain constant. (HOTS concept)

Question 17

Q17. Why are food chains generally limited to 3-5 trophic levels?

Accepted Answer

Option B: Energy available decreases at each trophic level. Only about 10% energy transfers to next trophic level, limiting chain length.

Question 18

Q18. A ray passes through the optical centre of a convex lens. It will:

Accepted Answer

Option C: Pass undeviated. A ray through the optical centre of a thin lens travels straight without deviation. (Commonly confused ray-diagram concept)

Question 19

Q19. Which compound belongs to the homologous series of carboxylic acids?

Accepted Answer

Option B: CH ₃ COOH. Carboxylic acids contain the -COOH functional group.

Question 20

Q20. A student connected three bulbs of equal resistance in parallel across a battery. If one bulb fuses, the other bulbs will:

Accepted Answer

Option C: Continue glowing normally. In parallel circuits, each bulb gets independent current path, so others continue working.

Mock Test 10 Performance Solutions

Detailed Question Analysis

Q1. Which of the following reactions is a decomposition reaction?

Q2. Which part of the eye controls the amount of light entering it?

Q3. Which cell organelle is known as the "powerhouse of the cell"?

Q4. Which of the following metals is least reactive?

Q5. Which process is responsible for transport of food in plants?

Q6. A student dipped an iron nail in copper sulphate solution and observed a colour change after some time. The blue colour faded because:

Q7. A heater marked \(1000\,\mathrm{W}\) operates for 2 hours. The electrical energy consumed is:

Q8. A potted plant kept near a window bends toward sunlight after a few days. This movement is due to:

Q9. Which property makes ionic compounds generally hard and brittle?

Q10. The valency of oxygen is:

Q11. Seat belts in cars reduce injuries during accidents because they:

Q12. Assertion (A): Rusting of iron is faster in coastal regions. Reason (R): Coastal air contains more moisture.

Q13. Assertion (A): Concave mirrors are used in vehicle headlights. Reason (R): Concave mirrors can produce parallel beams of light when source is placed at focus.

Q14. Case Study: A student tested four solutions using universal indicator. • Solution A \(\rightarrow\) p\(\mathrm{H_2}\) • Solution B \(\rightarrow\) pH 7 • Solution C \(\rightarrow\) pH 10 • Solution D \(\rightarrow\) pH 5 Which solution is most basic?

Q15. Case Study: A student performed an experiment using a concave mirror and observed a real inverted image on a screen. Which condition is definitely true?

Q16. A student claims that increasing voltage across a conductor always increases current. Which condition makes this statement incorrect?

Q17. Why are food chains generally limited to 3-5 trophic levels?

Q18. A ray passes through the optical centre of a convex lens. It will:

Q19. Which compound belongs to the homologous series of carboxylic acids?

Q20. A student connected three bulbs of equal resistance in parallel across a battery. If one bulb fuses, the other bulbs will:

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Mock Test 10 Performance Solutions

Detailed Question Analysis

Q1. Which of the following reactions is a decomposition reaction?

Q2. Which part of the eye controls the amount of light entering it?

Q3. Which cell organelle is known as the "powerhouse of the cell"?

Q4. Which of the following metals is least reactive?

Q5. Which process is responsible for transport of food in plants?

Q6. A student dipped an iron nail in copper sulphate solution and observed a colour change after some time. The blue colour faded because:

Q7. A heater marked \(1000\,\mathrm{W}\) operates for 2 hours. The electrical energy consumed is:

Q8. A potted plant kept near a window bends toward sunlight after a few days. This movement is due to:

Q9. Which property makes ionic compounds generally hard and brittle?

Q10. The valency of oxygen is:

Q11. Seat belts in cars reduce injuries during accidents because they:

Q12. Assertion (A): Rusting of iron is faster in coastal regions. Reason (R): Coastal air contains more moisture.

Q13. Assertion (A): Concave mirrors are used in vehicle headlights. Reason (R): Concave mirrors can produce parallel beams of light when source is placed at focus.

Q14. Case Study: A student tested four solutions using universal indicator. • Solution A \(\rightarrow\) p\(\mathrm{H_2}\) • Solution B \(\rightarrow\) pH 7 • Solution C \(\rightarrow\) pH 10 • Solution D \(\rightarrow\) pH 5 Which solution is most basic?

Q15. Case Study: A student performed an experiment using a concave mirror and observed a real inverted image on a screen. Which condition is definitely true?

Q16. A student claims that increasing voltage across a conductor always increases current. Which condition makes this statement incorrect?

Q17. Why are food chains generally limited to 3-5 trophic levels?

Q18. A ray passes through the optical centre of a convex lens. It will:

Q19. Which compound belongs to the homologous series of carboxylic acids?

Q20. A student connected three bulbs of equal resistance in parallel across a battery. If one bulb fuses, the other bulbs will:

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