CBSE Class 8 Answered

An electroscope detects the type of charge on a body.

It consists of a glass jar fitted with a cork lid and a metallic wire passing through it.

There are two metallic strips at the bottom of the wire.

The upper end of the wire is connected to a metal disc.

A positively charged object is touched to the metal disc, so that the charge is transferred to the metal strips through the wire and they diverge from each other on gaining a like charge.

A negatively charged object is brought into contact with the disc so that the strips converge towards each other, indicating the unlike charge on the body.

If the metal disc of the electroscope is touched with the hand, then it loses its charge to the ground by transfer of charge through the human body. This is called earthing.