Answer:
B.The charge on A is -q; there is no charge on B.
Explanation:
We are given that
Charge=+q
We have to find the correct statement.
When positive charge is placed at center of uncharged metal sphere
insulated from the ground then negative charge(-q) induced on inner
surface A of sphere and the outer surface B is grounded then the surface is neutral .
It means there is no charge on surface B.
Hence, option B is true .
B.The charge on A is -q; there is no charge on B.