Question

A magnetising field of $1600A{m}^{-1}$ produces a magnetic flux of $2.4\times 10^{-5}Wb$ in an iron bar of cross-sectional area $0.2c{m}^2$. The susceptibility of an iron bar is

• A. 298
• B. 596
• C. 1192
• D. 1788

Answer 1

Answer: (B)

Here, $H=1600A{m}^{-1},$
Magnetic flux $\left(\varphi \right)=2.4\times 10^{-5}Wb$
$A=0.2c{m}^2=0.2\times 10^{-4}{m}^2$
$\therefore B=\frac{\varphi }{A}=\frac{2.4\times 10^{-5}}{0.2\times 10^{-4}}=1.2Wb{m}^2$
$\therefore \mu =\frac{B}{H}=\frac{1.2}{1600}=7.5\times 10^{-4}N{A}^{-2}$
Hence, susceptibility $\chi =\frac{\mu }{{\mu }_0}-1=\frac{7.5\times 10^{-4}}{4\pi \times 10^{-7}}-1=596$