Question

A hollow sphere of radius R has a point charge Q at its centre. Electric flux emanating from it is `phi`. If both the charge and the radius of the sphere are doubled, electric flux emanating from the sphere will ______.

Options

• remain the same

• become `2phi`

• become `4phi`

• become `8phi`

Answer 1

A hollow sphere of radius R has a point charge Q at its centre. Electric flux emanating from it is `phi`. If both the charge and the radius of the sphere are doubled, electric flux emanating from the sphere will `bbunderline(become  2phi)`.

Explanation:

Since total electric flux passing through the spherical surface due to point charge Q at centre is

`phi = "q"/epsilon_0` where q = charge

If q' = 2q then

`phi"'" = "2q"/epsilon_0 = 2phi`