Question

A short electric dipole has dipole moment of $2.4\times {10}^{–10}\text{C-m}$. The electric potential due to the dipole at a point at a distance of $0.4\text{m}$ from the centre of the dipole situated on a line making an angle ${60}^{\circ }$ with the dipole axis is -

• A. $3.25\text{V}$
• B. $4.55\text{V}$
• C. $6.75\text{V}$
• D. $12.50\text{V}$

Answer 1

The correct option is C $6.75\text{V}$

The electric potential at any general point due to an electric dipole is given by,

$V=\frac{p\cos \theta }{4\pi {ϵ}_0{r}^2}$

Here, $p=2.4\times {10}^{–10}\text{C-m},r=0.4\text{m}$

So,

$V=\frac{2.4\times {10}^{-10}\times \cos {60}^{\circ }\times 9\times {10}^9}{(0.4{)}^2}=6.75\text{V}$