Question

12. When an electric dipole is placed in uniform electric field, which among the following is incorrect? ​

Answer 1

Answer:

Even if we change the orientation, the length and the charge of the dipole, the net force on the dipole will be equal to zero. Hence, the electric force on a dipole when it is placed in a uniform electric field is always zero. So, the correct answer is “Option A”.

For the diplole the electric field acting on the two charges never be equal. Hence the net electric field on the dipole cannot be zero. Thus electric force acting on the the two charges will never cancel each other.

For the torque acting on the dipole, first remember that in uniform electric field the torque becomes zero when the dipole becomes aligned to the electric field direction because the forces acting on the two charges is same but in case of non uniform electric field by point charge as the force acting on the charges are not equal and hence the torque acting would never be zero even when the dipole is aligned to electric field.