Question

Compute the torque experience by a magnetic needle in uniform

Answer 1

Explanation:

Work done in moving the needle in a uniform magnetic field from θ

1

to θ

2

=MB(cosθ

1

−cosθ

2

)

⟹W=MB(1−cos60

∘

)=

2

MB

Torque on magnetic needle at an angle θ with magnetic field, τ=MBsinθ=MBsin60

∘

=MB

2

3

=

3

W