# Class 12 Physics Electric Charges and Field: NCERT Solutions for Question 10

This page focuses on the detailed Electric Charges and Field question answers for Class 12 Physics Electric Charges and Field, addressing the question: 'An electric dipole with dipole moment 4 × 10−9 C m is aligned at 30° with the direction of a uniform electric field of magnitude 5 × 104N C−1. Calculate the magnitude of the torque acting on the dipole.'. The solution provides a thorough breakdown of the question, highlighting key concepts and approaches to arrive at the correct answer. This easy-to-understand explanation will help students develop better problem-solving skills, reinforcing their understanding of the chapter and aiding in exam preparation.
Question 10

## An electric dipole with dipole moment 4 × 10−9 C m is aligned at 30° with the direction of a uniform electric field of magnitude 5 × 104N C−1. Calculate the magnitude of the torque acting on the dipole.

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 ×

= 10-4 Nm

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