Question

crackling sound is heard while taking off a sweater during winters explain​

Answer 1

Answer:

becase opposite charges are producedon sweter

Answer 2

Explanation:

It is due to the collision of positive charged atoms of the sweater and negatively charged electrons (just like a spark in case when yoi touch a positive and negative current carrying wires with each other)

Now you would wonder from where the charges appear the answer is that this is due to a phenomena known as electrostaics each atom have positively charged nucleus surrounded by negatively charged electrons. Thus by rubbing simply you can also transmit some electrons from one body to the other (which in this case the electrons exchange occur between the sweater atoms and the air molecules)

Then why this phenomena does not occur during summer?

The answer is that in summer the air is humid and there are water molecules which absorbs the electrons and thus collision not occur.