Question

The radius of hollow metallic sphere is r If the potential difference between its surface and a at a distance 3r from its centre is v then the electric field intensity at a distance of 3r its centre is:

• A. V/2r
• B. V/3r
• C. V/4r
• D. V/6r

Answer 1

The correct option is D V/6r

The potential difference between the two0 point is $V$

$i.e.,$ $V=\frac{KQ}{r}-\frac{KQ}{3r}=\frac{2KQ}{3r}$

$E=\frac{KQ}{{\left(3r\right)}^2}=\frac{KQ}{9r^2}=\frac{V}{6r}$

Hence,

option $\left(D\right)$ is correct answer.