Question

State whether True or False :

In a uniform electric field, the dipole experiences no net force; but experiences a torque having a relation with $P$ and $E$ which is given by $\overrightarrow{P}\times \overrightarrow{E}$ where the parameters $P$ and $E$ have their usual meaning.

• A. True
• B. False

Answer 1

The correct option is A True

Torque ($\tau$) = Force × distance seperating forces

$\tau =dqEsin\theta$

Since dipole moment is given by $P=qd$
$\therefore \tau =PEsin\theta$ or
$\overrightarrow{\tau }=\overrightarrow{P}\times \overrightarrow{E}$.
In a uniform electric field, we know that the dipole experiences no net force; but experiences a torque having a relation with P and E is given by $\overrightarrow{\tau }=\overrightarrow{P}\times \overrightarrow{E}$ where the parameters P and E have their usual meaning.