The dielectric strength of air e 30times106 vm is the

Question

Solve the all parts of following problem:

Problem: The dielectric strength of air, E = 3.0×10⁶ V/m, is the maximum field that air can withstand before it breaks down and becomes conducting.

Part A: How much charge can be placed on a spherical conductor with a 12.0- cm radius before the field at its surface exceeds the breakdown strength of the air?

Part B: What would be the electric potential at the surface of this conductor?

Please show how you obtained the answer.