An electric dipole is placed in an electric field generated by a point charge.

Question

An electric dipole is placed in an electric field generated by a point charge. (A) The net electric force on the dipole must be zero. (B) The net electric force on the dipole may be zero. (C) The torque on the dipole due to the field must be zero. (D) The torque on the dipole due to the field may be zero.

Tardigrade Admin · Accepted Answer

Since electric field generated by point charge can never be same in magnitude and direction both, at two different points, so force on dipole can never be zero.
But, if dipole placed along field line, then torque will become zero.

Q. An electric dipole is placed in an electric field generated by a point charge.

The net electric force on the dipole must be zero.

The net electric force on the dipole may be zero.

The torque on the dipole due to the field must be zero.

The torque on the dipole due to the field may be zero.

Since electric field generated by point charge can never be same in magnitude and direction both, at two different points, so force on dipole can never be zero. But, if dipole placed along field line, then torque will become zero.

Since electric field generated by point charge can never be same in magnitude and direction both, at two different points, so force on dipole can never be zero.
But, if dipole placed along field line, then torque will become zero.