Question

If the potential (relative to infinity) due to a point charge is V at a distance R from this charge, the distance at which the potential (relative to infinity) is 2V is

A. 4R
B. 2R
C. R/2.
D. R/4

Answer 1

R/2

Step-by-step explanation:

The potential at a distance r is given by :

`V=(kq)/(r)`

Where

k is electrostatic constant

q is the charge

The potential (relative to infinity) due to a point charge is V at a distance R from this charge. So,

`(V_1)/(V_2)=(r_2)/(r_1)`

Put all the values,

`(V)/(2V)=(r_2)/(R)\\\\(1)/(2)=(r_2)/(R)\\\\r_2=(R)/(2)`

So, the distance at which the potential (relative to infinity) is 2V is R/2.