Question

An electric dipole with dipole moment 4*10^-9 C m is aligned at an angle 30 degree with the direction of a uniform electric field at magnitude 5*10^4N/C . Calculate the magnitude of the torque acting on the electric dipole.​

Answer 1

Given :

Electric dipole moment = 4 × 10¯⁹ Cm

Angle between dipole moment with an electric field = 30°

Electric field = 5 × 10⁴ N/C

To find :

The magnitude of the torque acting on the electric dipole

Solution :

Torque acting on the dipole is given by

τ = PE sinθ

Where

• P denotes dipole moment
• E denotes Electric field
• θ denotes angle between dipole moment with an electric field.

By substituting the given values,

$\dashrightarrow \: \sf \tau = PE \: sin \theta$

$\dashrightarrow \: \sf\tau =4 \times {10}^{ - 9} \times 5 \times {10}^{4} \times sin \: 30 \degree$

$\dashrightarrow \: \sf\tau = 20 \times {10}^{ - 5} \times \dfrac{1}{2}$

$\dashrightarrow \: \sf\tau = {10}^{ - 4} Nm$

Thus, the magnitude of the torque acting on the dipole is 10¯⁴ Nm.