Question

explain the working of electroscope

Answer 1

When the strips have a like charge and separate, the electroscope becomes charged. ... Electroscopes can also be used to detect various types of radiation from radioactive material. The electroscope, the first electrical measuring instrument, was invented by British physician William Gilbert.

Answer 2

A  simple electroscope consists of a glass jar resting on a wooden base. It is closed with an ebonite stopper having a hole. A brass rod passes through this hole. Two gold leaves are attached to the lower end of  the rod. A brass knob or disc is attached to the upper end of the rod. The glass vessels protects the gold leaves from air currents. Two strips of tin foils are fixed inside the bell jar facing the gold leaves. When the electroscope is in use, the metal foil is connected to the earth.