Question

The electric potential at a point on the equatorial line of an electric dipole is

• A. directly proportional to distance
• B. inversely proportional to distance
• C. inversely proportional to square of the distance
• D. none of the above

Answer 1

Answer: (D)

$\text{Step 1: Electric potential at P due to dipole}$$\text{[Refer Fig.]}$

Let OP be equatorial line.

Let $r$ be the distance of each charge from point P

Potential due to charge $q$ at point $P,V_1=\frac{kq}{r}$

Potential due to charge $-q$ at point $P,V_2=\frac{-kq}{r}$

$\text{Step 2: Total potential at point P}$

$V=V_1+V_2$

$\Rightarrow V=\frac{kq}{r}-\frac{kq}{r}=0$

Hence, the net potential at a point on the equatorial line of an electric dipole is zero.

Hence, Option (D) is correct.