Question Detail
Question
What are you likely to observe when a negatively charged rod is brought near the knob of a charged electroscope with a positive residual charge?
Correct Answer
Option A is the correct answer.
Detailed Explanation
The external negative rod repels free electrons in the electroscope away from the knob, down toward the leaf. This neutralises some of the leaf's excess positive charge, so the leaf's divergence decreases - it collapses.
Hint
The external negative rod repels free electrons in the electroscope away from the knob, down toward the leaf.