Physics Made Simple : Electrostatic Induction and Electroscope :

Electrostatic Induction

If in presence of a charged body,an insulated conductor has like charges at one end and unlike charges at the other end,then this is called Electrostatic Induction.

In this process,all charges remain static,that is why it is called as static.

Electroscope :

This is an instrument that is used to detect presence and nature of charge on a body.

Construction:

It consists of a brass rod that is attached to a brass disc on its top and two thin gold leaves at its lower end.

This assembly is mounted inside of a glass jar by mans of a cork so that the brass disc is projected outside.

A thin aluminium file is pasted on lower portion of glass jar and this foil is grounded by means of a gold file.

When any charge is transferred to electroscope,it spreads in the disc and leaves.

Due to force of repulsion between similar charges on the leaves,they diverge.

The divergence of leaves depends upon the quantity of charge on the leaves.

The divergence in the leaves of electroscope due to presence of a charged body is due to electrostatic induction.

Uses:

Electroscopes are used to distinguish between insulators and condcutors.