An iron sample having mass `8*4kg` is repeatedly taken over cycles of magnetisation and demagnetisation at a frequency of `50c//s`. It is fount that `3*2xx10^4J` of energy is dissipated as heat in the sample in `30min`. If density of iron is `7200km//m^3`, what is the hysterisis loss?

Answer

`304*8Jm^-3 cycl e^-1`

Explanation

Here, `m=8*4kg, v=50c//s`,
`t=30min=30xx60s`
Energy dissipated, `E=3*2xx10^4J`,
`rho=7200kg//m^3`
Volume, `V=m/rho=(8*4)/(7200)m^3`
Energy dissipated/ volume `=(3*2xx10^4xx7200)/(8*4)`
Hysterisis loss= Energy dissipated/volume/cycle
`=(3*2xx10^4xx7200)/(8*4xx30xx60xx50)=304*8Jm^-3 cycl e^-1`