A bar magnet of magnetic moment  ‘M’ is bent in the form of an arc which makes angle 600  . The percentage change in magnetic moment is

If the bar magnet is  bent  in the form of an arc  making an angle θ  at the centre then its new magnetic moment is                                 M1=2Msinθ2θ(rad) θ=60°=πC3 M1=2Msin30π×3 M1=2M×32(π)×3=3Mπ Percentage change in magnetic moment is                            ΔMM×100=M1-MM×100 =3Mπ-MM×100=3M-πMMπ×100 =M(3-π)Mπ×100=3-3.143.14×100                               = - 4.5% =Decreases by 4.5%