# Class 12 Physics Moving Charges and Magnetism: NCERT Solutions for Question 5

This page focuses on the detailed Moving Charges and Magnetism question answers for Class 12 Physics Moving Charges and Magnetism, addressing the question: 'What is the magnitude of magnetic force per unit length on a wire carrying a current of 8 A and making an angle of 30º with the direction of a uniform magnetic field of 0.15 T?'. 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 5

## What is the magnitude of magnetic force per unit length on a wire carrying a current of 8 A and making an angle of 30º with the direction of a uniform magnetic field of 0.15 T?

Current in the wire, I = 8 A

Magnitude of the uniform magnetic field, B = 0.15 T

Angle between the wire and magnetic field, Ω¸ = 30°.

Magnetic force per unit length on the wire is given as:

f= BI sinΩ¸

= 0.15 x 8 x 1 x sin30°

= 0.6 N m-1

Hence, the magnetic force per unit length on the wire is 0.6 N m-1.