Question

An electric dipole with dipole moment 4×10 to the power -9cm is aligned at 30 degree with the direction of a uniform electric field of magnitude 5×10 to the power 4N/C. Calculate the magnitude of the torque acting on the dipole.

Answer 1

Answer: 10√3×10-5

Explanation: Put the value of P, E and theta in the formula of torque.

Answer 2

Electric dipole moment, p = 4 × 10−9 C m (Given)

Angle made by p with a uniform electric field, θ = 30° (Given)

Electric field, E = 5 × 104 N C−1 (Given)

Torque acting on the dipole is given by the relation,

τ = pE sinθ

= 4 × 10-9 × 5 × 104 × sin 30

= 20 × 10-5 × 1 half

= 10-4 Nm

Therefore, the magnitude of the torque acting on the dipole is 10−4 N m.