Question

state the condition for stable equilibrium of an electric dipole placed in a uniform electric field

Answer 1

The dipole in an electric field will be in stable equilibrium if the following conditions are satisfied:

1. The torque on the dipole is zero, i.e., there is no rotatory motion of dipole.
2. The resultant force on dipole is zero, i.e., there is no translatory motion of dipole.
3. The potential energy of dipole is minimum.

It will be so when dipole is aligned along the direction of electric field.

The dipole will be in unstable equilibrium if

1. The torque on the dipole is zero.
2. The resultant force on dipole is zero.
3. The potential energy of dipole is maximum.

It will be so when dipole is aligned opposite to the direction of electric field.