Question

A solid sphere of radius R is charged
uniformly. At what distance from its surface
is the electrostatic potential half of the
potential at the centre?
1 R
2 R/2
3 R/3
4 2R​

Answer 1

Refer to the attached image ☺️

Answer 2

Answer:

3.) R / 3

Hence, at the distance from centre the electrostatic potential half of the potential at the centre = R/3

Explanation:

Radius of the sphere = R

Potential at the center of sphere is Vc =

= 3/2 × (kQ) / R

Potential at some distance x from center = KQ / x

Then, electrostatic potential half of the

potential at the centre :

By applying values in the formula, we get,

=> KQ / x = 1/2 × 3/2 × (KQ) / R

=> 3x = 4R

=> x = 4R / 3

Now, electrostatic potential half of the

potential at the centre = x - R

= 4R / 3 - R

= (4R - 3R) / 3

= R / 3

Hence, at the distance from the centre the electrostatic potential half of the potential at the centre = R/3