Question

The angle between, $\overrightarrow{p}$ electric dipole moment p and the electric field $\overrightarrow{E}$ when the dipole is in stable equilibrium

• A. 0
• B. $\pi /4$
• C. $\pi /2$
• D. $\pi$

Answer 1

Answer: (A)

The dipole is in stable equilibrium, when the torque on it is zero. Since $\overrightarrow{\tau }=\overrightarrow{p}\times \overrightarrow{E}$, therefore $\tau$ = 0 when the angle between $\overrightarrow{p}$ and $\overrightarrow{E}$ = 0.