Question

Which of the following is a reason for using woollen clothes in winter?
A) Wool is an insulator of heat.
B) It traps a layer of air in its fabric.
C) Air being an insulator doesn’t allow body heat to escape into the atmosphere.
D) All of the above.

Answer 1

Hint : We use woollen clothes to keep ourselves warm in cold climates. The working principle of woollen clothes involves the property of woollen clothes and air being bad conductors of heat.

Complete step by step answer
In option (A), wool is an insulator of heat which is correct as the woollen clothes are bad conductors of heat and they can separate your body temperature from the environment.
In option (B), Woollen clothes have fine pores filled with air such that it is trapped between our body and the clothes. Wool and air both are bad conductors of heat so their combined effect is a bad conductor of heat.
In option (C), the air that is trapped between our clothes and our body is a bad conductor of heat and won’t allow our body heat to escape into the environment. As a result, our body will be trapped inside and since we constantly generate body heat in a cool environment, the trapped heat will help in managing the temperature of our body and avoid it from decreasing.
Hence all the options are the correct reason for using woollen clothes in winter.
Therefore, the correct option is (D).

Note
We should always wear tight woollen clothes since if the air cannot be trapped between our body and the wool, it won’t help in conserving body heat. The main heat source though is the body heat that is trapped by the woollen clothes and helps us in keeping warm. In contrast, we wear soft fabrics such as cotton which allow air to circulate between the material and our body so that we can stay cool even in hot weather.