The Gold-leaf electroscope is a device used for detecting an electric charge and identifying its polarity.

It consists of a vertical conducting rod passing through a rubber stopper fitted in the mouth of a glass vessel.Two thin gold leaves are attached to lower end of the rod.

When the charged object touches the metal knob at the outer end of rod,the charge flows down to the leaves,The leaves diverge due to repulsion of the like charges they have recieved.

This experiment is based on the electrostatics law,that gives the surety of test.

The fundamental law of electroststics states that, like charges repel each-other and unlike charges attract each-other.