An electric dipole is kept in an electric field which is increasing in +x direction. The dipole moment of the dipole is also along the +x direction. Which of the following options is correct for the electric dipole.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Electric dipole will experience a net force in +x direction.
Given: Electric field $\mathbf{E}$ increases along +x, and dipole moment $\mathbf{p}$ is also along +x.
Force on positive charge: $+qE_+$ (toward +x)
Force on negative charge: $-qE_-$ (toward −x)
Since $E_+ > E_-$, net force acts in the direction of increasing field, i.e. +x direction.
Therefore, the dipole experiences:
• No torque (because $\mathbf{p} \parallel \mathbf{E}$)
• A net force in the +x direction
Hence, the dipole experiences a net force along +x but no torque.