Question

You are provided with a negatively charged gold leaf electroscope. State and explain what happens when an uncharged metal rod is brought near the disc of electroscope.

• A. Divergence increases
• B. Divergence decreases
• C. Divergence remains same
• D. Can't say

Answer 1

The correct option is B Divergence decreases

When uncharged rod is touched on the disc of a negatively charged gold leaf electroscope, the divergence between the gold leaves decreases as unlike charges attract each other. It is to be noted that a charged body can also attract an uncharged body, so repulsion is the sure test to determine whether the body is charged or not.
Therefore, when the uncharged rod is rolled on the disc of the negatively charged gold leaf electroscope, the electrons from the rod are transferred to the electroscope due to the negative charge and thus the rod becomes positively charged. Now the unlike charges attract each other and the divergence decreases.