Gujarati
5.Magnetism and Matter
medium

A bar magnet of length $10 \,cm$  and having the pole strength equal to $10^{-3}$ weber is kept in a magnetic field having magnetic induction $ (B)$  equal to $4\pi \times {10^{ - 3}}$ Tesla. It makes an angle of $30°$  with the direction of magnetic induction. The value of the torque acting on the magnet is

A

$2\pi \times {10^{ - 7}}\,N \times m$

B

$2\pi \times {10^{ - 5}}\,N \times m$

C

$0.5\,N \times m$

D

$0.5 \times {10^2}\,N \times m$

Solution

(a)Torque $\tau = M{B_H}\sin \theta $
$ = 0.1 \times {10^{ – 3}} \times 4\pi \times {10^{ – 3}} \times \sin {30^o} = {10^{ – 7}} \times 4\pi \times \frac{1}{2}$
$ = 2\pi \times {10^{ – 7}}\,N \times m$

Standard 12
Physics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.