Question

How woollen clothes keep us warm in winter?

Answer 1

Hint: Here we have asked the reason due to which woollen clothes keep us warm, so we will discuss here the conductivity of heat of the woollen. A material can conduct or transfer the heat through them, although it varies from material-to material. A good conductor of heat can transfer the heat easily while a poor conductor acts like an insulator and it won’t allow to transfer heat.

Complete answer:
Woollen fabrics basically trap air between them and air is a poor conductor of heat. So the heat which is radiated from the body also gets trapped due to the air between the woollen fabrics which doesn’t allow it to transfer the heat in the surrounding. We can also say that the woollen fabric is also a poor conductor of heat due to which it doesn’t allow the heat to transfer into the surrounding.

Additional information:
On the contrary, the cotton fabric is a good conductor of heat, therefore cotton clothes are preferred in summer. It transfers the heat radiated from the body in the environment keeping as cool.
Mostly metals are good conductors of heat whereas non-metals are bad conductors of heat.

Note:
The question specifically asks for the winter but it is a general thing that woollen clothes keeps us warm irrespective of the environment or season. Also note that as the woollen fabric does not allow heat to transfer into the surrounding, it also resists the heat flow from surrounding to the body.