Chapter 6, Problem 3STP

To determine

To explain: the effect on the two leaves, if a positively charged rod touches the knob of a negatively charged electroscope.

Explanation of Solution

Introduction:

A device that detects electric charge is known as an electroscope, it consists of two thin metal leaves attached to a metal rod. The electroscope, when is not charged then the leaves hang straight down. The electroscope, when is charged then the leaves are pushed apart.

In a negatively charged electroscope, the leaves have similar charges (negative), so they repel each other. When a positively charged rod touches the knob of the negatively charged electroscope, the leaves will move closer together. The positive charges from the rod will attract some of the negative charge on the leaf. On decrease of negative charges on the leaves, the leaves will repel less than before.

Conclusion:

The two leaves will move closer together.