Question

an electric dipole has maximum potential energy in a uniform external electric field. the angle between electric dipole moment and electric field​

Answer 1

The potential energy is -P*E*cos(theta) where P is the dipole moment, E is the electric field and theta is the angle dipole makes with the field.

Also in this case we take theta=90° as a point of zero potential energy(reference).

Answer 2

An electric dipole has maximum potential energy in a uniform external electric field. the angle between electric dipole moment and electric field​

Explanation:

​When the angle between the dipole moment and electric field is 180° then the potential energy of the electric dipole is maximum.