Question

Two charges +3µC and -3µC are separated by a very small distance of 5 mm.

1. What is the name of the above arrangement? 

2. If the above arrangement is placed in a uniform electric field of intensity 3 × 10^-5 N/C with its axis perpendicular to the field direction. What is the torque acting on it?

3. If the arrangement is placed in a non uniform electric field, what happens?

Answer 1

1. Electric dipole.

2.  \(\tau\) = P × E

= PE (θ = 90°) = q2aE

= 3 × 10⁶ × 5 × 10³ × 3 × 10⁵ Nm(∴ 2a = 5 × 10^-3)

3. The dipole undergoes for both translation and rotational motion.