1) A metal sphere carries a charge 5*10^-9C and is at potential 0f 400V, relative to the potential far away. the potential at the center of the sphere is:

2) A 5cm radius isolated conducting sphere is charged so its potential is +100V relative to the potential far away. The charge density on the surface is:

3) A conductinf sphere has charge Q and its electric potential is V, relative to the potential far away. the charge is doubled to 2Q, the potential is:

4) The potential difference between its ends of a 2m stick that is parallel to a uniorm electric field is 400V. The magnitude of the electric field is:

5) The work required to carry a particle with charge of 6C from 5V eqipotential surface to a 6V eqipotential surface and back again to the 5V surface is: