Question

A short electric dipole has dipole moment of $3\sqrt{2}\times {10}^{-10}\text{C m}$. The electric potential due to the dipole at a point which is at a distance $0.3\text{m}$ from the centre of the dipole, situated on a line making an angle of ${45}^{\circ }$ with the dipole axis is $(\frac{1}{4\pi {ϵ}_0}=9\times {10}^9{\text{N m}}^2/{\text{C}}^2)$ :

• A. $300\text{V}$
• B. $30\text{V}$
• C. $200\text{V}$
• D. $20\text{V}$

Answer 1

The correct option is B $30\text{V}$

Electric potential due to an electric dipole at any general point is given as,

$V=\frac{kp\cos \theta }{r^2}$

Where $\theta$ is angle with dipole axis.

$V=\frac{9\times {10}^9\times 3\sqrt{2}\times {10}^{-10}}{9\times {10}^{-2}\times \sqrt{2}}=30\text{V}$