A steel wire of length $l$ has a magnetic moment M. It is bent into L shape from the middle. The new magnetic moment is
Answer & explanation
Correct answer: option 2
Magnetic moment M = mL
if we bent it from middle then effective length i.e length between its end become $\frac{L}{\sqrt2}$
new Magnetic moment = m$\frac{L}{\sqrt2}$ = $\frac{M}{\sqrt2}$