Question

how will you use a electroscope find the nature of change on a body

Answer 1

U will take the body that u want to test whether it is charged or not and touch it with disc of the electroscope. If the body is charged, metal being a good conductor of electricity, conducts charge to the gold leaves of the electroscope and bcos they both acquire same kind of charge, they will become wide open showing repletion. Thus, in short, if the leaves become wide open, the body is charged if not the body is not charged.

THIS IS IN THE CASE OF GOLD-LEAF ELECTROSCOPE