Question

What is the energy of electric dipole in electric field in stable equilibrium

Answer 1

For unstable equilibrium, potential energy is maximum at equilibrium position. A dipole in a uniform electric field is in stable or unstable equilibrium according as the angle between the dipole and electric field is 0 or 180.

Answer 2

Potential energy of an electric dipole in a uniform electric field is given by the following equation.

U = p E cos θ

Where,

p is electric dipole moment

E is electric field

θ is angle between p and E

In stable equilibrium position, the angle between p and E is 0 degree.  

Therefore, Potential energy = p E cos 0 = p E

In stable equilibrium, the potential energy posses a minimum value.