An electric dipole of dipole moment p is placed in the position of stable equilibrium in uniform electric field of intensity E. This is rotated through an angle theta from the initial position. The potential energy of the electric dipole in the final position is (1) -pE cos theta (2) pE (1-cos theta) (3) pE cos theta (4) pE sin theta

Q. An electric dipole of moment p is placed in the position of stable equilibrium in uniform electric field of intensity E. If it is rotated through an angle $\theta$ from the initial position, the potential energy of electric dipole in the final position is

Q. An electric dipole of moment p is placed in the position of stable equilibrium in uniform electric field of intensity E. If it is rotated through an angle $\theta$ from the initial position, the potential energy of electric dipole in the final position is

Q. An electric dipole of moment 'p' is placed in an electric field of intensity 'E'. The dipole acquires a position such that the axis of the dipole makes an angle 0 with the direction of the field. Assuming that the potential energy of the dipole to be zero when $\theta ={90}^0$, the torque and the potential energy of the dipole will respectively be:

Q. Potential energy of a dipole in an external field
Electric potential energy of an Electric dipole in dipole from zero energy position to the desired position (The zero enrgy position to be one when the dipole When an electric dipole of dipole moment p is on it such that $P=\underset{P}{\overset{}{\to }}\times \underset{E}{\overset{}{\to }}$
This torque tends to rotate the dipole let dW the small amount of work done. turning the dipole through an angle $d\theta$
$dW=Text.d\theta$
$=pEsin\theta d\theta$
W is the work done in turning the dipole from $0^{o}to\theta$ then,
$W={\int }_0^{W}dW$
= ${\int }_{{90}^o}^{\theta }pEsin\theta d\theta$

Q. An electrical dipole of dipole moment ${}^{\prime }{p}^{\prime }$ is placed in an electric field of intensity ${}^{\prime }{E}^{\prime }$. The dipole acquires a position such that the axis of the dipole makes an angle $\theta$ with electric field. Assuming that the potential energy of the dipole to be zero when $\theta ={90}^{\circ }$, the torque on dipole and the potential energy of the dipole will be respectively