Question

A student touches an electroscope with a negatively charged rod, and the leaves of the electroscope separate. What will be the result when a second positively charged rod is brought near, but kept close to the electroscope without touching ?

• A. The leaves will begin to flutter
• B. The leaves will separate further
• C. The leaves will move closer together
• D. The leaves will be unaffected
• E. None of the above will happen

Answer 1

Answer: (C)

The leaves will move closer together

When the negatively charged rod is touched to the electroscope, the electroscope also attains negative charge and so do the leaves. Hence the leaves move apart due to repulsion.
When a positively charged rod is brought near, the negative charges from the leaves move towards the other part of the electroscope, and hence the negative charges in leaves decreases and hence the leaves move together due to lesser repulsion.