Assertion and Reason Questions and Answers

Answer: C

Correct answer: A is true but R is false.

CFCs have been phased out under the Montreal Protocol, so A is true. But they do not themselves cause cancer: they destroy stratospheric ozone, and it is the extra ultraviolet reaching the ground that raises the risk of skin cancer. R is false as a direct reason.

Answer: B

Correct answer: Both A and R are true but R is NOT the correct explanation of A.

Both statements are true, but being an alloy of copper and tin is not why bronze is chosen for statues. It is chosen because it flows well into a mould, expands slightly as it sets so as to take up fine detail, and resists corrosion out of doors. R does not explain A.

Answer: A

Correct answer: Both A and R are true and R is the correct explanation of A.

Black money circulates outside the tax and banking system, adding to the demand for goods without adding to their supply and so pushing prices up. Failing to check its growth therefore feeds inflation directly. Both are true and R explains A.

Answer: C

Correct answer: A is true but R is false.

Leaves are green, so A is true. But the green pigment is chlorophyll, held in chloroplasts; chromoplasts carry the red, orange and yellow pigments of flowers and fruits. R is false.

Answer: C

Correct answer: A is false but R is true.

White surfaces reflect radiant heat well, so R is true - and that is why white is worn in summer. In winter dark clothes, which absorb heat, are preferred, so A is false.

Answer: C

Correct answer: A is true but R is false.

A leak can be smelt, so A is true. But LPG is odourless in itself: ethyl mercaptan is added in tiny quantities precisely so that leaks announce themselves. R is false as stated.

Answer: A

Correct answer: Both A and R are true and R is the correct explanation of A.

Simla stands at about 2200 m against Delhi’s 220 m, and air cools by roughly \( 6.5^{\circ}\mathrm{C} \) per kilometre of ascent. The altitude difference therefore accounts for the temperature difference directly. Both are true and R explains A.

Answer: B

Correct answer: Both A and R are true but R is NOT the correct explanation of A.

Both statements are true, but the reason given is the wrong half of the cycle. Land heats quickly by day, which drives the sea breeze; at night it also cools quickly, so the air over it becomes denser and flows out to sea. It is the rapid cooling, not the rapid heating, that produces the land breeze. R does not explain A.

Answer: A

Correct answer: Both A and R are true and R is the correct explanation of A.

Ice forms only at the surface and, being less dense than water, floats there and insulates the water below, which stays liquid at about \( 4^{\circ}\mathrm{C} \). The fish therefore survive beneath it. Both are true and R explains A.

Answer: C

Correct answer: Both A and R are false.

Humid air is already close to saturation, so sweat evaporates more slowly, not faster - and since evaporation is what cools the body, hot humid weather feels oppressive. Both A and R are false.