JEE PYQ: Electrostatics Question 60
Question 60 - 2019 (11 Jan Shift 2)
An electric field of 1000 V/m is applied to an electric dipole at angle of $45°$. The value of electric dipole moment is $10^{-29}$ C.m. What is the potential energy of the electric dipole?
(1) $-20 \times 10^{-18}$ J
(2) $-7 \times 10^{-27}$ J
(3) $-10 \times 10^{-29}$ J
(4) $-9 \times 10^{-20}$ J
Show Answer
Answer: (2)
Solution
$U = -\vec{p} \cdot \vec{E} = -pE\cos\theta = -10^{-29} \times 1000 \times \cos 45° = -10^{-26} \times \frac{1}{\sqrt{2}} = -0.707 \times 10^{-26} = -7 \times 10^{-27}$ J.
BETA
