An electric dipole with dipole moment $\vec{p}$ is placed in a uniform electric field $\vec{E}$. The net force on the dipole is:

Solution

1. An electric dipole consists of two charges, $+q$ and $-q$, separated by a distance $d$.
2. In a uniform electric field $\vec{E}$, the force on the positive charge is ${\vec{F}}_{+}=q\vec{E}$ and the force on the negative charge is ${\vec{F}}_{-}=-q\vec{E}$.
3. The net force on the dipole is the vector sum of these two forces: $$\begin{array}{rl}{\vec{F}}_{net}& ={\vec{F}}_{+}+{\vec{F}}_{-}\\ & =q\vec{E}-q\vec{E}\\ & =0\end{array}$$.
4. Hence the answer is (A).