Question

How much work is required to turn an electric dipole 180° in a uniform electric field of magnitude E = 46.0 N/C if the dipole moment has a magnitude of p = 3.02 × 10−25 C·m and the initial angle is 64°?

Answer 1

Answer:

$W=1.22*10^{-23}J$

Explanation:

Torque and energy of an electric dipole in an electric field we find:

$W=U(\alpha_{o}+\pi )-U(\alpha_{o} )=-pE(cos(\alpha_{o}+\pi )-cos(\alpha_{o} ))\\W=2pECos\alpha_{o}\\ W=2(3.02*10^{-25}C.m )(46.oN/C)Cos64\\W=1.22*10^{-23}J$