Question

How will you use a gold leaf electroscope to find out whether the charge on a charged body is positive or negative?

Answer 1

(a) Charge negatively the gold-leaf electroscope by conduction i.e. To detect the kind of charge by a positively charged gold leaf electroscope touching the disc of GL.E. with negatively charged ebonite rod. The leaves diverge (because of repulsion) Note the divergence as shown in figure (a).
(b) Bringa charged body to be tested in contact with the disc. If divergence in leaves increases, it has a similar charge i.e. negative as shown in figure (b)
(c) If divergence decrease, the body has opposite charge i.e. positive charge as shown in figure (c).