A magnetising field of `1600 Am^(-1)` produces a magnetic flux `2.4 xx 10^(-5)` weber in an iron bar of cross-sectional area `0.2 cm^(2)` . The susceptibility of the iron bar will be

Options

A. 1788
B. 1192
C. 596
D. 298

Explanation

`mu = (B)/(H) = (phi)/(AH)`
`= (2.4 xx 10^(-5))/(0.2 xx 10^(-4) xx 16 xx 10^(2))`
`= (2.4 xx 10^(-5))/(16 xx 2 xx 10^(-3))`
`= (1.2)/(16) xx 10^(-2)`
`(3)/(4) xx 10^(-3)`
`= 0.75 xx 10^(-3)` Wb/m A
`mu_(r) = (0.75 xx 10^(-3))/( 4 pi xx 10^(-7))`
`mu_(r) = (75)/(4pi ) xx 10^(2)`
`= 5.9713376`
`mu_(r) = 597`
`chi_(m) = mu_(r) -1`
`chi_(m) = 597-1`
`chi_(m) = 596`