Question 1

Q1. Which of the following is an example of an endothermic reaction?

Accepted Answer

Option C: Photosynthesis. Photosynthesis absorbs sunlight energy to convert carbon dioxide and water into glucose.

Question 2

Q2. The splitting of water molecules during photosynthesis is called:

Accepted Answer

Option B: Photolysis. Light energy splits water molecules into hydrogen and oxygen during photosynthesis.

Question 3

Q3. Which part of the human brain controls balance and posture?

Accepted Answer

Option C: Cerebellum. The cerebellum coordinates muscular activities and maintains body balance.

Question 4

Q4. Which of the following has the highest resistance?

Accepted Answer

Option C: Nichrome wire. Nichrome has high resistivity and is commonly used in heating elements.

Question 5

Q5. Which of the following organisms is placed at the first trophic level?

Accepted Answer

Option C: Grass. Producers like green plants occupy the first trophic level in a food chain.

Question 6

Q6. A student observed that magnesium ribbon burns with a dazzling white flame and forms a white ash. The ash formed is:

Accepted Answer

Option B: Magnesium oxide. Magnesium reacts with oxygen during burning to form magnesium oxide.

Question 7

Q7. Two resistors of 3 Ω and 6 Ω are connected in parallel. The equivalent resistance is:

Accepted Answer

Option B: 2 Ω. 1/R = 1/3 + 1/6 = 1/2 Therefore, R = 2 Ω (Tricky parallel combination question)

Question 8

Q8. A student observed that leaves of a plant wilt after excessive transpiration. This happens because:

Accepted Answer

Option B: Water loss exceeds water absorption. Wilting occurs when transpiration rate becomes higher than water uptake by roots.

Question 9

Q9. Which statement about covalent compounds is generally correct?

Accepted Answer

Option C: They are formed by sharing of electrons. Covalent bonds form when atoms share electrons to attain stable electronic configuration.

Question 10

Q10. The atomic number of an element is determined by the number of:

Accepted Answer

Option C: Protons. Atomic number equals the number of protons present in the nucleus.

Question 11

Q11. Food packets are often flushed with nitrogen gas because nitrogen:

Accepted Answer

Option C: Prevents oxidation of food. Nitrogen is less reactive and helps prevent spoilage due to oxidation.

Question 12

Q12. Assertion (A): Distilled water does not conduct electricity well. Reason (R): Distilled water lacks dissolved ions.

Accepted Answer

Option A: Both A and R are true and R is correct explanation of A. Electric conduction in liquids requires free ions, which are absent in distilled water.

Question 13

Q13. Assertion (A): Concave mirrors are used by dentists. Reason (R): Concave mirrors can produce enlarged erect images when object is close.

Accepted Answer

Option A: Both A and R are true and R is correct explanation of A. When the object lies between pole and focus, concave mirrors form magnified erect images useful for examination.

Question 14

Q14. Case Study: A student tested the pH of different household substances. • Toothpaste → pH 9 • Lemon juice → pH 2 • Soap solution → pH 11 • Milk → pH 6.5 Which substance is most acidic?

Accepted Answer

Option B: Lemon juice. Lower pH values indicate stronger acidic nature.

Question 15

Q15. Case Study: A student performed an experiment using a convex lens. When the object was moved from beyond 2F to between F and 2F, the image formed became:

Accepted Answer

Option B: Larger and real. For object between F and 2F, convex lens forms enlarged real inverted image beyond 2F.

Question 16

Q16. A student claims that all transparent materials refract light equally. Which option disproves this statement?

Accepted Answer

Option A: Glass and water have different refractive indices. Different transparent materials bend light differently because of varying refractive indices. (HOTS concept)

Question 17

Q17. Why is aluminium preferred for making overhead electric cables?

Accepted Answer

Option C: Lightweight and good conductor. Aluminium is lighter and sufficiently conductive, making it suitable for transmission lines.

Question 18

Q18. A convex mirror always forms images between:

Accepted Answer

Option A: Pole and focus. Images formed by convex mirrors are always virtual and lie between pole and focus behind the mirror. (Commonly confused concept)

Question 19

Q19. Which hydrocarbon contains a triple bond?

Accepted Answer

Option C: Ethyne. Alkynes contain at least one triple bond. Ethyne is the simplest alkyne.

Question 20

Q20. An electric bulb is rated 220 V, 100 W. If operated at 220 V, the current drawn will be:

Accepted Answer

Option A: 0.45 A. Using I = P/V = 100/220 ≈ 0.45 A

Mock Test 08 Performance Solutions

Detailed Question Analysis

Q1. Which of the following is an example of an endothermic reaction?

Q2. The splitting of water molecules during photosynthesis is called:

Q3. Which part of the human brain controls balance and posture?

Q4. Which of the following has the highest resistance?

Q5. Which of the following organisms is placed at the first trophic level?

Q6. A student observed that magnesium ribbon burns with a dazzling white flame and forms a white ash. The ash formed is:

Q7. Two resistors of 3 \(\Omega\) and 6 \(\Omega\) are connected in parallel. The equivalent resistance is:

Q8. A student observed that leaves of a plant wilt after excessive transpiration. This happens because:

Q9. Which statement about covalent compounds is generally correct?

Q10. The atomic number of an element is determined by the number of:

Q11. Food packets are often flushed with nitrogen gas because nitrogen:

Q12. Assertion (A): Distilled water does not conduct electricity well. Reason (R): Distilled water lacks dissolved ions.

Q13. Assertion (A): Concave mirrors are used by dentists. Reason (R): Concave mirrors can produce enlarged erect images when object is close.

Q14. Case Study: A student tested the pH of different household substances. • Toothpaste \(\rightarrow\) pH 9 • Lemon juice \(\rightarrow\) p\(\mathrm{H_2}\) • Soap solution \(\rightarrow\) pH 11 • Milk \(\rightarrow\) pH 6.5 Which substance is most acidic?

Q15. Case Study: A student performed an experiment using a convex lens. When the object was moved from beyond 2F to between F and 2F, the image formed became:

Q16. A student claims that all transparent materials refract light equally. Which option disproves this statement?

Q17. Why is aluminium preferred for making overhead electric cables?

Q18. A convex mirror always forms images between:

Q19. Which hydrocarbon contains a triple bond?

Q20. An electric bulb is rated \(220\,\mathrm{V}\), \(100\,\mathrm{W}\). If operated at \(220\,\mathrm{V}\), the current drawn will be:

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Mock Test 08 Performance Solutions

Detailed Question Analysis

Q1. Which of the following is an example of an endothermic reaction?

Q2. The splitting of water molecules during photosynthesis is called:

Q3. Which part of the human brain controls balance and posture?

Q4. Which of the following has the highest resistance?

Q5. Which of the following organisms is placed at the first trophic level?

Q6. A student observed that magnesium ribbon burns with a dazzling white flame and forms a white ash. The ash formed is:

Q7. Two resistors of 3 \(\Omega\) and 6 \(\Omega\) are connected in parallel. The equivalent resistance is:

Q8. A student observed that leaves of a plant wilt after excessive transpiration. This happens because:

Q9. Which statement about covalent compounds is generally correct?

Q10. The atomic number of an element is determined by the number of:

Q11. Food packets are often flushed with nitrogen gas because nitrogen:

Q12. Assertion (A): Distilled water does not conduct electricity well. Reason (R): Distilled water lacks dissolved ions.

Q13. Assertion (A): Concave mirrors are used by dentists. Reason (R): Concave mirrors can produce enlarged erect images when object is close.

Q14. Case Study: A student tested the pH of different household substances. • Toothpaste \(\rightarrow\) pH 9 • Lemon juice \(\rightarrow\) p\(\mathrm{H_2}\) • Soap solution \(\rightarrow\) pH 11 • Milk \(\rightarrow\) pH 6.5 Which substance is most acidic?

Q15. Case Study: A student performed an experiment using a convex lens. When the object was moved from beyond 2F to between F and 2F, the image formed became:

Q16. A student claims that all transparent materials refract light equally. Which option disproves this statement?

Q17. Why is aluminium preferred for making overhead electric cables?

Q18. A convex mirror always forms images between:

Q19. Which hydrocarbon contains a triple bond?

Q20. An electric bulb is rated \(220\,\mathrm{V}\), \(100\,\mathrm{W}\). If operated at \(220\,\mathrm{V}\), the current drawn will be:

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