Electroscope

An electroscope is a tool used to demonstrate the effects of electric charges, conduction, and induction. For example, with a metal electroscope, by holding a charged rod near the bulb at the top, the opposite charges are attracted to the top and the like charges are repelled to the vanes at the bottom, causing them to tilt and separate. If you ground the scope while still holding the charged rod near, the like charges are repelled to the ground, leaving only opposite charges on the metal. If th