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:

Let the pole strength be $m$. Original magnetic moment $M=m\cdot L$.When bent at the middle, each arm has length $L/2$.The distance between the two poles (effective length $L^{\prime }$) is the third side of an equilateral triangle (since arms are $L/2$ and the angle is $60^{\circ }$).Thus, $L^{\prime }=L/2$.New magnetic moment $M^{\prime }=m\cdot L^{\prime }=m\cdot (L/2)=\frac{M}{2}$.