Question

An electric dipole of dipole moment $\overrightarrow{p}$ is placed in a uniform electric field $\overrightarrow{E}$. The maximum torque experienced by the dipole is

• A. $pE$
• B. $p/E$
• C. $E/p$
• D. $\overrightarrow{p}.\overrightarrow{E}$

Answer 1

Answer: (A)

$pE$

The torque due to the electric dipole is $\overrightarrow{\tau }=\overrightarrow{p}\times \overrightarrow{E}=pE\sin \theta$

where $\theta$, angle between the dipole and the electric field.

For maximum torque, $\sin \theta =1$

So, ${\tau }_{max}=pE$