Question

A magnetising field of `1500 A//m` produces a flux of `2*4xx10^-5` weber in a bar of iron of cross-sectional area `0*5cm^2`. Calculate the permeability and susceptibility of the iron bar used.

Answer 1

Correct Answer - `255`; `254`
Here, `H=1500A//m`, `phi=2*4xx10^-5weber`
`a=0*5cm^2=0*5xx10^-4m^2`
`mu_r=?`, `chi_m=?`
Now `B=phi/a=(2.4xx10^-5)/(0*5xx10^-4)=4*8xx10^-1T`
`mu=B/H=(4*8xx10^-1)/(1500)=3*2xx10^-4`
`mu_r=(mu)/(mu_0)=(3*2xx10^-4)/(4pixx10^-7)=0*255xx10^3=255`
As `mu_r=1+chi_m :. chi_m=mu_r-1=255-1=254`