Question

An electric dipole when placed in a uniform electric field will have minimum potential energy,if the angle between dipole moment and electric field is

• A. zero
• B. $\pi/2$
• C. $\pi$
• D. $3\pi/2$

Answer 1

Answer: (A)

zero

Answer 2

The potential energy of a dipole in an electric field is, $-\vec{p} \cdot \vec{E}$ The potential energy is thus minimum when $p$ and $E$ are in the same direction.