Question

A charged body is brought near a positively charged gold leaf electroscope. The divergence of its leaves increases. If the same body is brought near a negatively charged gold-leaf electroscope, what will be the effect on the divergence of its leaves?

Answer 1

Hint: Electroscope is a device used for detecting the presence of electric charges by attraction or repulsion. It also determines the type of charge whether it is a positive or negative charge. In this device, two pieces of gold leaves are enclosed in a glass-walled chamber.

Complete step by step answer:
Step I:
In an electroscope, there is a process to determine the type of charge and hence the effect on divergence. It is already given that the charged body increases the divergence of the electroscope. Divergence in a gold leaf electroscope basically indicates the amount of charge transferred from any external source to the gold leaf.
Step II:
Suppose if the negatively charged body is brought near the electroscope, the divergence increased. It happened because the electrons from the gold leaves get shifted due to induction. The amount of negative charge increases as like charges repel each other. The divergence will also increase as it shows the amount of charge transferred.
Step III:
In an electroscope, if the object has a positive charge then it will pull up electrons up to the top terminal. But if the object has a negative charge, then it will repel electrons from the top terminal.

$\therefore$ If the charged body is brought near the negatively charged electroscope, its divergence will increase.

Note:
There can be a question as to why there is only a gold leaf used in an electroscope for determining the presence of charges? This is because gold is a metal that is highly malleable. This means that it can be converted into very thin, small, and light sheets to be enclosed in the chamber.