Question

the energy needed to rotate an electric dipole p from in uniform electric field E from the position of stable equilibrium to unstable equilibrium is​

Answer 1

Answer:

The dipole would do work in the reverse process. Thus work W = 2pE would be done on rotating the dipole from the state of stable equilibrium (ϴ = 0) to the state of unstable equilibrium (ϴ = 180). ... The work done to rotate the dipole through an elementary angle dϴ is dW = (p E sin ϴ) dϴ.

Explanation:

hope it helps you

Answer 2

in case of a stable equilibrium the dipole is making an angle (theta1 ) with electric field.

then initial energy of dipole= - PEcos(theta1)

now in case of unstable equilibrium the dipole is making an angle (theta2) with the electric field then

final potential energy of dipole is

= - PEcos(theta2)

now as we know that work done in rotating a dipole is given by = final energy of dipole - initial energy of dipole

= -PEcos(theta2) - [-PEcos(theta2)]

= PE(cos(theta1) - cos(theta2))