Magnetism and Matter - Result Question 6
«««< HEAD:content/english/neet-pyq-chapterwise/physics/magnetism-and-matter/magnetism-and-matter-result-question-6.md
9. A bar magnet, of magnetic moment $\vec{M}$, is placed in a magnetic field of induction $\vec{B}$. The torque exerted on it is
======= ####9. A bar magnet, of magnetic moment $\vec{M}$, is placed in a magnetic field of induction $\vec{B}$. The torque exerted on it is
3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/magnetism-and-matter/magnetism-and-matter—result-question-6.md (a) $\vec{M} \cdot \vec{B}$
(b) $-\vec{M} \cdot \vec{B}$
(c) $\vec{M} \times \vec{B}$
(d) $\vec{B} \times \vec{M}$
Show Answer
Answer:
Correct Answer: 9. (c)
Solution:
- (c) We know that when a bar magnet is placed in the magnetic field at an angle $\theta$, then torque acting on the bar magnet $(\tau)$
$=M B \sin \theta=\vec{M} \times \vec{B}$.
The direction of torque $(\tau)$ is perpendicular to the plane containing $M$ and $B$ and is given by right hand screw rule.
