Discuss the working of a gold-leaf electroscope. How can it determine the nature and magnitude of charge on a body?

Solution & explanation

A metal cap connects through an insulating support to a stem and thin leaf. Charge redistribution gives the stem and leaf like signs, so the leaf diverges. Compare a known precharge: additional divergence suggests the same sign, initial decrease the opposite under controlled approach. Divergence gives a qualitative comparison, not an exact charge measurement without calibration; an uncharged electroscope alone cannot determine sign.