An electric dipole is placed in a non-uniform electric field, such that the dipole moment is parallel to the electric field. The dipole will experience
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → a force only
Force on an electric dipole in a non-uniform electric field:
$\vec{F} = (\vec{p} \cdot \nabla) \vec{E}$
If dipole moment $\vec{p}$ is parallel to the electric field $\vec{E}$, the dipole experiences a net force in the direction of increasing field strength. No torque acts because $\vec{p} \parallel \vec{E}$.
The dipole will experience a net force along the direction of the electric field.