Question

When a glass rod is rubbed with a piece of silk cloth the rod

• A. and the cloth both acquire positive charge.
• B. becomes positively charged while the cloth has a negative charge.
• C. and the cloth both acquire negative charge.
• D. becomes negatively charged while the cloth has a positive charge.

Answer 1

Answer: (B)

becomes positively charged while the cloth has a negative charge.

Answer 2

Silk is rubbed on a glass rod, and the act of rubbing charges both the rod and the silk. Electrons go from one body to another, giving one a negative charge and the other a positive charge. Because silk can attract electrons more readily than glass, it has a higher electron affinity. Thus, glass gains a tiny positive charge and silk a slight negative charge.

The correct option is (B): becomes positively charged while the cloth has a negative charge.