Chapter 12, Problem 1CQ

When two different materials are rubbed together, do the two materials acquire the same type of charge or different types of charge? Explain how you could justify your answer with a simple experiment.

To determine

Whether two materials which are rubbed together acquire similar or opposite charge.

Answer to Problem 1CQ

The two materials which are rubbed together acquire opposite charges.

Explanation of Solution

Electric charge is a conserved quantity. When two materials are rubbed together, one material will lose electron and the other material will gain. So the total electric charge of the two materials remains same. The one which loses electron will become positively charged, while the one who accepts electron will become negatively charged. Thus two materials which are rubbed together acquire opposite charges.

As an example when a glass rod is rubbed in a silk cloth, the glass rod will acquire positive charge while the silk acquires negative charge.

Conclusion:

The two materials which are rubbed together acquire opposite charges.