Question

The electric field due to a uniformly charged sphere of radius $R$ as a function of the distance from its centre is represented graphically by

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

Outside the spherical charge, the intensity of electric field at a point $P$ situated at a distance $r$ from the centre of the charge is

$E=\frac{1}{4\pi {\epsilon }_0}\frac{q}{r^2}(\text{ if }r>R)$
On the surface of spherical charge the electric field is given by
$E=\frac{1}{4\pi {\epsilon }_0}\frac{q}{r^2}$ (if $r=R)$
and inside the spherical charge the electric field is
$E=\frac{1}{4\pi {\epsilon }_0}\frac{qr}{R^3}$ (if $r<R)$
Hence, the variation of $E-r$ is a follows :