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Given below are two statements, one is labelled as Assertion (A) and the other as Reason (R).
Assertion (A) : Evaporation of sweat from human skin dissipates body heat.
Reason (R) : High humidity on a hot day increases discomfort.
Select the correct answer from the code given below :
Code :
Explanation
Assertion (A) is true: Evaporation is a cooling process. When sweat evaporates from the skin, it changes phase from liquid to gas. This phase change requires energy, known as the latent heat of vaporization, which is absorbed from the body, thereby dissipating heat and lowering body temperature.
Reason (R) is true: High humidity refers to a high concentration of water vapor in the air. When humidity is high, the air's capacity to absorb more moisture is reduced, which slows down the rate of sweat evaporation. Consequently, the body's natural cooling mechanism becomes less effective, leading to increased discomfort and a higher perceived temperature (heat index).
Relationship: While both statements are factually correct, (R) describes a physiological consequence of suppressed evaporation, whereas the physical principle behind (A) is latent heat. Thus, (R) is not the logical explanation for (A).
SIMILAR QUESTIONS
Given below are two statements, one is labelled as Assertion (A) and the other as Reason (R).
Assertion (A) : Relative humidity decreases with increasing air temperature.
Reason (R) : Absolute humidity increases with increasing evaporation.
Select the correct answer from the codes given below :
Given below are two statements, one is labelled as Assertion (A) and the other as Reason (R).
Assertion (A) : During the 20th century, poverty and poor people have become the subject of our concern and duty.
Reason (R) : Strategically there was lack of targeted actions due to which this issue got momentum.
Select the correct answer from the code given below :
Code :
Given below are two statements, one is labelled as Assertion (A) and other as Reason (R) :
Assertion (A) : Human body synthesises all the vitamins required by it.
Reason (R) : Vitamins are essential for proper growth of the body.
Select the correct answer using the codes given below.
Codes :