It is known that electric force a charged body is given as $\vec{F} = q \vec{E}$ given that $\vec{E}$ is uniform. Now, for an ideal dipole, what would we take as the charge for calculating the force exerted on it by an external electric field?
Electromagnetism – Can an Ideal Dipole Experience an Electric Force?
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Best Answer
The electric force on a dipole is $\mathbf F=(p \cdot \boldsymbol \nabla ) \mathbf E$, where $p$ is the dipole moment, $\mathbf E$ is the electric field, and $\boldsymbol \nabla$ is the gradient operator.
Note that this force goes to zero for a uniform field (as mentioned in another answer). Note also that there will be a torque to align the dipole with the field.