Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectric Field and Potential
An electric dipole is placed within an electric field produced by a point charge.
Options
- AThe net electric force on the dipole could be zero
- BThe net electric force on the dipole must always be zero
- CThe torque on the dipole due to the field must always be zero
- DThe torque on the dipole due to the field could be zero
Correct answer
D. The torque on the dipole due to the field could be zero
Step-by-step solution
The electric field produced by a point charge is non-uniform, as its magnitude varies with distance and its direction is radial. Since the two charges of the dipole are at different positions, they will experience different electric fields ( E ₁ E ₂ ). The net force on the dipole is F _ net = q E ₁ - q E ₂ 0 . Thus, the net electric force can never be zero. The torque on the dipole is given by = p E . If the dipole is placed such that its dipole moment p is parallel or anti-parallel to the electric field E (i.e., o