Question

An iron rod of $0.2c{m}^2$ cross - sectional area is subjected to a magnetizing field of $1200A{m}^{-1}$. The susceptibility of iron is 599. The magnetic flux produced is :

• A. $0.904Wb$
• B. $1.81\times {10}^{-5}Wb$
• C. $0.904\times {10}^{-5}Wb$
• D. $5.43\times {10}^{-5}Wb$

Answer 1

Answer: (C)

$0.904\times {10}^{-5}Wb$

Given,

${\mu }_0=4\pi \times {10}^{-7}Wb/Am$

$H=1200A{m}^{-1}$

$\chi =599$

The permeability of the iron rod is given by

$\mu ={\mu }_0(1+\chi )$

$\mu =4\times 3.14\times {10}^{-7}(1+599)=7.536\times {10}^{-4}H/m$

The magnetic field produced is,

$B=\mu H$

$B=7.536\times {10}^{-4}\times 1200=0.904T$

The magnetic flux per unit area is $0.904\times {10}^{-5}Wb$

The correct option is C.