Which is the instrument to detect the charge on the body ? Explain it with diagram.

A simple apparatus to detect charge on a body is the gold-leaf electroscope as shown in figure.

It consists of a vertical metal rod housed in a box, with two thin gold leaves attached to its bottom end.

When a charged object touches the metal knob at the top of the rod, charge flows on to the leaves and they diverge.

The degree of divergence is an indicator of the amount of charge.