Physics - Heat & Thermo Question with Solution | TestHub
Assertion: In sufficiently dry air, an earthen pitcher can cool its contents below the ambient air temperature.
Reason: Water that seeps to the porous surface evaporates and removes latent heat.
Options:
Answer:
Solution:
A porous earthen pitcher lets water seep to the outer surface, where it evaporates and takes latent heat from the water inside. In hot dry summer this cooling is strong. In the rainy season the air is humid and evaporation is almost nil, so the pitcher gets no benefit; the pitcher is also a poor conductor and keeps its heat. The brass vessel conducts heat well, so its water follows the cooler rainy-season air temperature more closely. The ranking of the two water temperatures in rainy weather cannot be determined from humidity alone. Both are true. The Reason gives the physical cause of the Assertion. Correct option: (A).
