alleryStart learning →When placed in a uniform external electric field, an electric dipole experiences
Aa net force but no torque
Bboth a net force and a net torque
Cneither force nor torque
Da torque but no net force
Answer & Solution
Correct answer: D. a torque but no net force
1. The forces on $+q$ and $-q$ in a uniform field are equal and opposite, so the **net force is zero**.
2. These forces form a couple, giving a torque $\vec{\tau} = \vec{p}\times\vec{E}$, magnitude $pE\sin\theta$.
3. Thus a dipole in a uniform field only rotates; it does not translate.
_Source: Samacheer Kalvi Class 12 Physics Vol.1, Unit 1 'Electrostatics', §1.4.3_
Keep practising Electromagnetism
Browse all Electromagnetism questions for Tamil Nadu HSC (Class 12), or explore more Physics topics.
Related questions
On the axial line of a short dipole the electric field is $E_a$, and on the equatorial linThe energy stored in a capacitor of capacitance $C$ charged to voltage $V$ (holding chargeBy Gauss's law, the total electric flux through a closed surface enclosing a net charge $QA parallel-plate capacitor has capacitance $C$. If BOTH the plate area and the plate separAn equipotential surface is one on whichThe relation between the electric field and the electrostatic potential isIf the voltage across a capacitor is increased from $V$ to $2V$, thenPoints A and B are at potentials $+7\ V$ and $-4\ V$. The work done in moving 50 electrons