Exam

NEET

Year

2013

Subject

Physics

Chapter

Magnetic Effects of Current

NEET 2013 · Physics · Magnetic Effects of Current

A bar magnet of magnetic moment M placed at right angles to a...

A bar magnet of magnetic moment $M$ placed at right angles to a magnetic induction $B$. If a force $F$ is experienced by each pole of the magnet. The length of the magnet will be:

Step-by-step solution

Here $$\begin{aligned} \tau& =\vec{M} \times \vec{B}\\ |\tau| & =M B \sin 90^{{}^{\circ}} \end{aligned}$$ and we know that\tau=F l$\therefore F l=\mathrm{MB} \quad \Rightarrow$ l=$\frac{M B}{F}$