Chapter 20.1, Problem 7SSC

To determine

To explain: The condition of copper rod when it is rubbed with wool.

Answer to Problem 7SSC

Copper remains neutral

Explanation of Solution

Introduction:

Insulating materials becomes charged by rubbing against each other. This is called charging by friction. While rubbing these materials, the electrons (negatively charged) are rubbed off from one material and move in to another material. The material which lost its electrons becomes positively charged and the material which gains electrons becomes negatively charged.

Copper is a conducting material. Therefore it is not possible to produce charge on it by friction as long as it is in person’s hand. This happens because there will be a flow of charge and thus copper remains neutral.