Question

A dipole of electric dipole moment p is placed in a uniform electric field of strength E. If $\theta$ is the angle between positive directions of p and E, then the potential energy of the electric dipole is largest when $\theta$is

• A. $\frac{\pi}{4}$
• B. $\frac{\pi}{2}$
• C. $\pi$
• D. Zero

Answer 1

Answer: (C)

$\pi$

Answer 2

: The potential energy of an electric dipole in a uniform electric field is

$U = \overrightarrow{P}.\overrightarrow{E}$

$U = - pE\cos\theta$

For U to be maximum,

$\cos\theta = - 1 \Rightarrow \theta = \pi$