Torque acting on a electric dipole in a uniform electric fiels $\hat E$
$\begin{array}{1 1} (a)\; Torque=\overrightarrow{p}.\hat E \\ (b)\;Torque=|\overrightarrow{p}||\hat E| \cos \theta\\ (c) Torque =\overrightarrow{P} \times \overrightarrow{E} \\ (d) Torque =\large\frac{\overrightarrow{P} \times \overrightarrow{E}}{2} \end{array}$