Correct answer: (d) Both (A) and (R) are true and (R) is the correct explanation of (A)
Explanation
- A
(A) is false but (R) is true
(a) claims that (A) is false but (R) is true. However, both statements are factually correct regarding the temperature difference between Agra and Darjeeling, making this option incorrect.
- B
(A) is true but (R) is false
(b) claims that (A) is true but (R) is false. This is incorrect because the scientific principle stating that temperature decreases with altitude is well-established and accurately applied here.
- C
Both (A) and (R) are true but (R) is not the correct explanation of (A)
(c) claims that both statements are true but (R) is not the correct explanation of (A). This is incorrect because the difference in temperature between Agra (plains) and Darjeeling (hills) at the same latitude is directly caused by the difference in their elevation.
- D
Both (A) and (R) are true and (R) is the correct explanation of (A)
(d) claims that both statements are true and (R) is the correct explanation of (A). Assertion (A) accurately notes that Agra and Darjeeling share similar latitudes yet experience vastly different January temperatures of 16°C and 4°C respectively. Reason (R) correctly explains this phenomenon by citing the normal lapse rate, where temperature decreases with height due to thinner air in mountainous regions like Darjeeling compared to the plains of Agra. Therefore, this option is the correct key.
Summary. Official key is (d) because both the assertion regarding temperature differences and the reason concerning lapse rate with altitude are scientifically accurate. Agra and Darjeeling lie on roughly similar latitudes, which would typically imply similar solar radiation, but elevation plays a decisive role. Darjeeling's high altitude results in significantly lower temperatures compared to Agra in the plains. Reason (R) provides the exact physical explanation for this climatic variation. Thus, both statements are true and mutually supportive.