Choose the correct alternative from the following.
Assertion (A) : We prefer to wear white clothes in winter.
Reason (R) : White clothes are good reflectors of heat.
Answer: D
Correct answer: A is false but R is true.
White surfaces do reflect radiant heat well, so R is true. But that is why white is worn in summer; in winter dark clothes, which absorb heat, are preferred. A is false.
Please log in or register to report this question.
Assertion (A) : Leakages in household gas cylinders can be detected.
Reason (R) : LPG has a strong smell.
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.
Please log in or register to report this question.
Assertion (A) : Simla is colder than Delhi.
Reason (R) : Simla is at a higher altitude as compared to Delhi.
Answer: A
Correct answer: Both A and R are true and R is the correct explanation of A.
Simla is colder than Delhi, and it stands at about 2200 m against Delhi’s 220 m. Air cools by roughly \( 6.5^{\circ}\mathrm{C} \) for every kilometre of ascent, so the altitude difference accounts for the temperature difference directly. Both are true and R explains A.
Please log in or register to report this question.
Assertion (A) : Land breeze blows during night.
Reason (R) : Land gets heated up quickly.
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.
Please log in or register to report this question.
Assertion (A) : The freezing of sea water during winter does not kill the fishes.
Reason (R) : Only surface water is frozen.
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 it floats there, insulating the water beneath. The layer below stays liquid at about \( 4^{\circ}\mathrm{C} \), where water is densest, so the fish survive. Both are true and R explains A.
Please log in or register to report this question.
Assertion (A) : We feel comfortable in hot and humid climate.
Reason (R) : Sweat evaporates faster in humid climate.
Answer: D
Correct answer: Both A and R are false.
Humid air is already near 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.
Please log in or register to report this question.
Assertion (A) : Mohammad-bin-Tughluq is called the 'wisest fool'.
Reason (R) : He had wise plans but implemented them foolishly.
Answer: A
Correct answer: Both A and R are true and R is the correct explanation of A.
Muhammad-bin-Tughluq’s schemes - the token currency, the transfer of the capital to Daulatabad, the Deccan campaigns - were imaginative in conception and disastrous in execution. That combination is exactly what earned him the name. Both are true and R explains A.
Please log in or register to report this question.
Assertion (A) : Weeds should not be allowed to grow along with crops.
Reason (R) : Weeds leave no space for plants to grow.
Answer: C
Correct answer: A is true but R is false.
Weeds must be kept out of a crop, so A is true. But the reason given is not the real one: weeds do their damage by competing for water, nutrients and light and by sheltering pests, rather than merely by taking up room. R is false.
Please log in or register to report this question.
Assertion (A) : Carbon dioxide turns lime water milky.
Reason (R) : Carbon dioxide sullies the water.
Answer: C
Correct answer: A is true but R is false.
Carbon dioxide does turn lime water milky, so A is true. But the milkiness is a precipitate of insoluble calcium carbonate: \[ \mathrm{Ca(OH)_2 + CO_2 \rightarrow CaCO_3 \downarrow + H_2O} \] not any “sullying” of the water. R is false.
Please log in or register to report this question.
Assertion (A) : Diamond is used for cutting glass.
Reason (R) : Diamond has a high refractive index.
Answer: B
Correct answer: Both A and R are true but R is NOT the correct explanation of A.
Diamond does cut glass and it does have a high refractive index, so both statements are true - but they are unconnected. Diamond cuts glass because it is the hardest natural substance; its refractive index is why it sparkles. R does not explain A.
Please log in or register to report this question.
