Question

A pole of strength $m_p$ is produced when a magnetic material of cross-sectional area $A$ is placed in a magnetic field of strength $H$. The total magnetic flux will be

• A. ${\mu }_0(AH+m_p)$
• B. ${\mu }_{0}AH$
• C. ${\mu }_0{m}_p$
• D. ${\mu }_0[m_{p}AH+A]$

Answer 1

The correct option is A ${\mu }_0(AH+m_p)$

$\varphi =BA,B={\mu }_0(I+H)\varphi ={\mu }_0(I+H)A$ and $I=\frac{m_p}{A}$
$\varphi ={\mu }_0\left(\frac{m_p}{A}+H\right)A={\mu }_0(m_p+AH)$