OnlineCBT
Physics · PYQ NEET UG 2025
हिन्दीAn electric dipole with dipole moment \( 5 \times 10^{-6}\text{ Cm} \) is aligned with the direction of a uniform electric field of magnitude \( 4 \times 10^5\text{ N/C} \). The dipole is then rotated through an angle of \( 60^\circ \) with respect to the electric field. The change in the potential energy of the dipole is :
Correct answer · Option 2
\( 1.0\text{ J} \)
Explanation
Change in potential energy \( \Delta U = -pE \cos\theta_2 - (-pE \cos\theta_1) = -pE(\cos 60^\circ - \cos 0^\circ) = -(5 \times 10^{-6})(4 \times 10^5)(0.5 - 1) = 1.0\text{ J} \).
