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1. The formation of magnesium oxide is correctly shown in option:

A. B. C. D.

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2. The metals obtained from their molten chlorides by the process of electrolytic reduction are

A. Gold and silver B. Calcium and magnesium C. Aluminium and silver D. Sodium and iron

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3. In one formula unit of salt 'X', seven molecules of water of crystallisation are present. The salt 'X' is

A. CuSO₄ B. Na₂CO₃ C. FeSO₄ D. CaSO₄

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4. Reaction between two elements A and B, forms a compound C. A loses electrons and B gains electrons. Which one of the following properties will not be shown by compound C?

A. It has high melting point B. It is highly soluble in water C. It has weak electrostatic forces of attraction between its oppositely charged ions D. It conducts electricity in its molten state or aqueous solution

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5. Electrolysis of water is a decomposition reaction. The mass ratio (M_H M_O) of hydrogen and oxygen gases liberated at the electrodes during electrolysis of water is

A. 8:1 B. 2:1 C. 1:2 D. 1:8

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6. Consider the following reactions:

(i) Dilute hydrochloric acid reacts with sodium hydroxide.

(ii) Magnesium oxide reacts with dilute hydrochloric acid.

(iii) Carbon dioxide reacts with sodium hydroxide.

It is found that in each case

A. Salt and water is formed B. Neutral salts are formed C. Hydrogen gas is formed D. Acidic salts are formed

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7. The products formed when Aluminium and Magnesium are burnt in the presence of air respectively are

A. Al₃O₄ and MgO₂ B. Al₂O₃ and MgO C. Al₃O₄ and MgO D. Al₂O₃ and MgO₂

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8. The plant hormone whose concentration stimulates the cells to grow longer on the side of the shoot which is away from light is

A. Cytokinins B. Gibberellins C. Adrenaline D. Auxins

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9. Secretion of less saliva in mouth will affect the conversion of

A. proteins into amino acids B. fats into fatty acids and glycerol C. starch into simple sugars D. sugars into alcohol

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10. If pea plants with round and green seeds (RRyy) are crossed with pea plants having wrinkled and yellow seeds (rrYY), the seeds developed by the plants of F₁ generation will be

A. 50% round and green B. 75% wrinkled and green C. 100% round and yellow D. 75% wrinkled and yellow

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11. The correct/true statement(s) for a bisexual flower is/are:

(i) They possess both stamen and pistil.

(ii) They possess either stamen or pistil.

(iii) They exhibit either self-pollination or cross-pollination.

(iv) They cannot produce fruits on their own.

A. (i) only B. (iv) only C. (i) and (iii) D. (i) and (iv)

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12. The breakdown of glucose has taken the following pathway:

The sites ‘a’ and ‘b’ respectively are

A. Mitochondria and Oxygen deficient muscle cells B. Cytoplasm and Oxygen rich muscle cell C. Cytoplasm and Yeast cells D. Cytoplasm and Oxygen deficient muscle cells

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13. The white light entering a glass prism gets split into its constituent colours. It is observed that

A. Red light deviates the most B. Violet light deviates the least C. Yellow light deviates more than the blue light D. Green light deviates more than the orange light

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14. Mirror 'X' is used to concentrate sunlight in a solar furnace and Mirror 'Y' is fitted on the side of the vehicle to see the traffic behind the driver. Which of the following statements are true for the two mirrors?

(i)The image formed by mirror 'X' is real, diminished and at its focus.

(ii)The image formed by mirror 'Y' is virtual, diminished and erect.

(iii)The image formed by mirror 'X' is virtual, diminished and erect.

(iv)The image formed by mirror 'Y' is real, diminished and at its focus.

A. (i) and (ii) B. (ii) and (iii) C. (iii) and (iv) D. (i) and (iv)

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15. The percentage of solar energy which is not converted into food energy by the leaves of green plants in a terrestrial ecosystem is about

A. 1% B. 10% C. 90% D. 99%

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16. Which of the following groups do not constitute a food chain?

(i) Wolf, rabbit, grass, lion

(ii) Plankton, man, grasshopper, fish

(iii) Hawk, grass, snake, grasshopper, frog

(iv) Grass, snake, wolf, tiger

A. (i) and (iv) B. (i) and (iii) C. (ii) and (iii) D. (ii) and (iv)

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17. Assertion (A): A human child bears all the basic features of human beings.
Reason (R): It looks exactly like its parents, showing very little variations.

A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A). B. Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A). C. Assertion (A) is true, but Reason (R) is false. D. Assertion (A) is false, but Reason (R) is true.

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18. Assertion (A): The amount of ozone in the atmosphere began to drop sharply in the 1980s. Reason (R): The oxygen atoms combine with molecular oxygen to form ozone.

A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A). B. Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A). C. Assertion (A) is true, but Reason (R) is false. D. Assertion (A) is false, but Reason (R) is true.

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19. Assertion (A): Decomposition reactions are generally endothermic reactions. Reason (R): Decomposition of organic matter into compost is an exothermic process.

A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A). B. Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A). C. Assertion (A) is true, but Reason (R) is false. D. Assertion (A) is false, but Reason (R) is true.

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20. Assertion (A): No two magnetic field lines are found to cross each other. Reason (R): The compass needle cannot point towards two directions at the point of intersection of two magnetic field lines.

A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A). B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A). C. Assertion (A) is true, but Reason (R) is false. D. Assertion (A) is false, but Reason (R) is true.