Question

The space inside a straight current carrying solenoid is filled with a magnetic material having magnetic susceptibility equal to $1.2 \times 10^{-5}$. What is fractional increase in the magnetic field inside solenoid with respect to air as medium inside the solenoid?

• A. $1.2 \times 10^{-5}$
• B. $1.2 \times 10^{-3}$
• C. $1.8 \times 10^{-3}$
• D. $2.4 \times 10^{-5}$

Answer 1

Answer: (A)

$\chi=1.2 \times 10^{-5} $
$\mu_{ r }=1+\chi=1+1.2 \times 10^{-5}$
Fractional Change
$=\frac{\Delta B }{ B }=\frac{\mu_{0} \mu_{ r } ni -\mu_{0} ni }{\mu_{0} ni }=\left(\mu_{ r }-1\right) $
$=1.2 \times 10^{-5}$