An iron bar of length $L$ has magnetic moment $M$. It is bent at the middle of its length such that

Question

An iron bar of length $L$ has magnetic moment $M$. It is bent at the middle of its length such that the two arms make an angle $60^{\circ}$ with each other. The magnetic moment of this new magnet is :

Professor PC Thomas Classes · Answer

b)\ $\begin{aligned} & M_{\mathrm{net}}=\sqrt{\left(\frac{M}{2}ight)^2+\left(\frac{M}{2}ight)^2+2 \frac{M}{2} \cdot \frac{M}{2} \cos 120^{\circ}} \ & M_{\mathrm{net}}=\sqrt{\frac{M^2}{4} 	imes 2-\frac{M^2}{4}}=\sqrt{\frac{M^2}{4}}=\frac{M}{2}\end{aligned}$