Assertion and Reason Questions and Answers

Answer: C

Correct answer: A is true but R is false.

A body immersed in a liquid does weigh less, so A is true. But by Archimedes’ principle the loss equals the weight of the liquid displaced, not any “higher density” of that liquid - which need not be higher at all. R is false.

Answer: D

Correct answer: A is false but R is true.

Baking soda, sodium bicarbonate, is indeed alkaline, so R is true. But that is why it relieves acidity: it neutralises the excess hydrochloric acid in the stomach. It does not create acidity, so A is false.

Answer: A

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

The Himalayan rivers rise in glaciers and snowfields, which melt through the summer and keep the channels flowing even when the monsoon has failed. Peninsular rivers, fed only by rain, dry up. Both are true and R explains A.

Answer: C

Correct answer: Both A and R are false.

Amoebiasis is an infection of the intestine caused by the protozoan Entamoeba histolytica, spread through contaminated food and water - it is not tied to any occupation. Inhaled asbestos dust causes asbestosis, a quite different disease. Both A and R are false.

Answer: A

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

Plaster of Paris takes up water and sets within minutes into a hard mass of gypsum. That is precisely why a bandage soaked in it can be moulded round a limb and left to harden, holding the broken bone still. Both are true and R explains A.

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.