Question

The mass of a specimen of a ferromagnetic material is 0.6 kg. and its density is `7.8 xx 10^(3) kg//m3`. If the area of hysteresis loop of alternating magnetising field of frequency 50Hz is 0.722 MKS units then the hysteresis loss per second will be

A. `27.77 xx 10^(-5)`J
B. `2.777 xx 10^(-5) J`
C. `27.77 xx 10^(-4) J`
D. `27.77 xx 10^(-6) J`

Answer 1

Correct Answer - C
If V= volume of the material =mass / density ,
Area = area of hysteresis loop ,
v= frequency of alternate magnetic field applied and t= time for which field is applied then , energy loss in the material in t second is
`E=VA " "vt=((m)/(d))A " "bvt`
`=(0.6)/(7.8 xx 10^(3)) xx 0.722 xx 50 xx 1 =2.77 xx 20^(3) =27.7 xx 10^(-4)J`