Question

An electric dipole of moment $\overrightarrow{p}$ is placed in a uniform electric field$\overrightarrow{E}$ . Then
(i) The torque on the dipole is $\overrightarrow{p}\times \overrightarrow{E}$.
(ii) The potential energy of the system is $\overrightarrow{p}\cdot \overrightarrow{E}$.
(iii) The resultant force on the dipole is zero.
Choose the correct option.

• A. (i), (ii) and (iii) are correct
• B. (i) and (iii) are correct and (ii) is wrong
• C. Only (i) is wrong
• D. (i) and (ii) are correct and (iii) is wrong

Answer 1

The correct option is A (i), (ii) and (iii) are correct

In a uniform electric field, $\overrightarrow{E}$, dipole experiences a torque $\overrightarrow{\tau }$ given by $\overrightarrow{\tau }=\overrightarrow{p}\times \overrightarrow{E}$ but experiences no force. The potential energy of the dipole in a uniform electric field $\overrightarrow{E}$ is $U=-\overrightarrow{p}.\overrightarrow{E}$