Choose the correct statement
(a) Two thin woolen blankets keep ou body warmer than a single equally thick woolen blanket
(b) Mud houses with thatcvhed roofs keep warm in summer and cool in winter as compared to concrete housed

Options

A. Only A
B. Only B
C. Both A and B
D. None of these

Answer

A

Explanation

Two thin woolen blankets are warmer than a thick woolen blanket, because there is an extra layer of air trapped between thin blankets, which acts as an insulator and does not allow the heat from the body to flow out. Mud houses with thatched roofs keep cool in summer and warm in winter as compared to concrete houses, because the thatched roof contains a large amount of trapped air. Similarly, mud is a bad conductor of heat. Hence, in summer the heat from outside does not flow in and in winter, the heat from inside does not flow out. Thus, they remain cool in summer and warm in winter.