Question

sometimes a crackling sound is heard while taking off sweater during winter explain

Answer 1

sweater is made of wool and generally shirt we wear is made of cotton blended with some synthetic fibres. Constant friction between the shirt and sweater let's transfer of electrons from one material to the other. This results in building of electric potential. When enough potential has been accumulated, while taking of the sweater it discharges and transfer of electrons take place. Passage of electrons through air in the forms of spark let out heat and sound energy. Thus, we hear the crackling sound and in dark rooms we may see the spark lights as well........................ Hope it makes easy for you....

Answer 2

Answer:

When we take out sweater, Woolen sweater gets charged due to friction between the sweater and the body. This results in crackling sound.