Question

explain how a pith ball electroscope works?

Answer 1

A pith ball electroscope is shown in Fig. It consists of a small pith ball suspended with the help of a dry silk thread from an insulating stand.
The working of the electroscope:

To find out whether the body is charged or uncharged : The body is brought near the pith ball (without touching it). If the pith ball shows a movement towards the body, the body is charged, but if the pith ball remains static the body is uncharged.

To find out whether the body has a positive charge or a negative charge : First of all, a pith ball electroscope is charged positively by conduction. Now the charged body is brought near the electroscope. If the pith ball moves away the body has a positive charge, but if the body moves towards the body, it is negatively charged.

Answer 2

ELECTROSCOPE :

Electroscope is used to detect and measure electric charges.

WORKING OF AN ELECTROSCOPE :

•In an uncharged electroscope, the leaves hang straight down.

•When a charged object touches the metal knob, electric charges travel down the rod and into the leaves.

•The leaves spread apart, indicating the presence of an electric charge.

•Since the charge on both leaves is the same the leaves repel each other and spread out.

CONSTRUCTION OF AN ELECTROSCOPE :

An electroscope consists of a metal rod with a knob at the top and a pair of thin metal leaves at the bottom. The rod is inserted in a one hole rubber stopper which fits into a flask. The flask contains the lower part of the rod and the metal leaves.