Ans. DETECTING THE PRESENCE OF CHARGE
In order to detect the presence of charge on anybody, bring the body hear the disk of an uncharged electroscope. If the body is neutral, there will be no deflection of the leaves (Fig.13.5-a). But if the body is positively or negatively charged, the leaves of the electroscope diverge. For example, if the body is negatively charged then due to electrostatic induction positive charge will appear on the disk while negative charge will appear on the leaves (Fig.13.5rb). The leaves of electroscope repel each other and diverge because each leave gets similar charge. The 'divergence of leaves will depend on the amount of charge.