A large metal sphere mounted on an insulating stand is negatively charged. A smaller, uncharged metal sphere mounted on an insulating stand is placed near to the negatively charged sphere. The smaller sphere is connected to the Earth by a conducting wire. Electrons flow from the smaller sphere to Earth because they are repelled by the larger sphere. The smaller sphere is then disconnected from the Earth. Which row must be correct about the particles in the larger sphere and the final charge of the smaller sphere?

Answer:

11) C

It is important to think about this question logically.

The smaller sphere was initially uncharged (equal number of protons and electrons).
Then, when the small sphere was connected to the Earth, electrons started to flow from small sphere to Earth. This means that the small sphere started to lose electrons (i.e. started to lose negative charge). Hence when the small sphere was disconnected, its final charge would be positive. (more protons than electrons).

The larger sphere was initially negative charged (more electrons than protons). It was not connected to anything at any point in time. So, it would remain the same, i.e. negative charged and hence it would have fewer protons than electrons.

So, C is the answer.