Question

A positively charged metal rod is brought near an uncharged pith ball that is being touched by a copper wire. Both the rod and the copper wire are simultaneously removed, Identify the induced charge on pith ball?

• A. The pith ball has been positively charged by conduction
• B. The pith ball has been positively charged by induction
• C. The pith ball has been negatively charged by conduction
• D. The pith ball has been negatively charged by induction
• E. The pith ball has not been charged in any way

Answer 1

The correct option is D The pith ball has been negatively charged by induction

Due to the presence of the positively charged metal rod, negative charges accumulate at the pith ball, being sourced from the copper wire. Equal amount of positive charge was induced in the copper wire.

When suddenly both rod and copper wire are removed, the negative charges remain on the pith ball, and hence it becomes negatively charged.