Why can a dipole have torque in a uniform electric field even when net force is zero?
Correct answer: A
In a uniform field, the positive and negative charges of a dipole experience forces of equal magnitude in opposite directions, so their vector sum is zero. However, the forces act at separate locations, forming a couple. The couple produces torque τ = pE sin θ, which can rotate the dipole even though the net force is zero. Thus option A is correct; B confuses two different physical quantities, while C and D are false.