Question

Electric potential at a point P, r distance away due to a point charge q at A is V volts. If twice of this charge is distributed uniformly on the surface of a hollow sphere of radius 4r with center at point A, the potential at P now is :

• A. V
• B. V/2
• C. V/4
• D. V/8

Answer 1

The correct option is B V/2

Potential at P due to point charge is $V=\frac{kq}{r}$

Since radius of hollow sphere is $R=4r$ so point P inside the hollw sphere.Now the potential at P $=V_{in}=V_{surface}=\frac{k\left(2q\right)}{R}=\frac{2kq}{4r}=\frac{kq}{2r}=V/2$