Q 12-02-005NEETNEET 2025Top questionEasy
An electric dipole with dipole moment $5 \times 10^{-6}$ C m is aligned with the direction of a uniform electric field of magnitude $4 \times 10^5$ N/C. The dipole is then rotated through an angle of $60°$ with respect to the electric field. The change in the potential energy of the dipole is :
Answer: (B) $1.0$ J
Concept. $U = -pE\cos\theta$.
Step 1. Change. $pE(\cos0° - \cos60°) = 2 \times 0.5 = 1.0$ J.
Answer. $1.0$ J (Option B).
Solution by Sreeraj P, M.Sc Physics