A bar magnet of magnetic moment 10 Am2 has a cross sectional area of 2.5×10−4 m2. If the intensity of magnetization of the magnet is 106 A/m, the length of magnet is
0.4m
0.04cm
0.04m
40 cm
GivenMagnetic moment M=10 Am2Cross sectional Area A=2.5×10−4 m2∴ Intensity of magnetization I=MV∵V=AL
I=MAL
⇒I=102.5×10−4×L
⇒L=102.5×10−4×106
∴L=4×10−2 m