A conducting sphere of radius 20 cm has a charge Q placed on it producing a field of magnitude E₀ at its surface. More charge is added to the surface until the magnitude of the field at the surface is 2 E₀. How much charge was added to the surface?

Question

Quizplus · Accepted Answer

The electric field at the surface of a conducting sphere is given by $E = \frac{kQ}{r^2}$, where $E$ is the electric field, $k$ is Coulomb's constant, $Q$ is the charge, and $r$ is the radius of the sphere. If the electric field doubles, it means the charge must also double to maintain the relationship, as the radius remains constant. Therefore, the amount of charge added to double the field is $Q$, making the total charge $2Q$.

A Conducting Sphere of Radius 20 Cm Has a Charge