Question

A solenoid has a core of a material with relative permeability $400$. The winding of the .solenoid are insulated from the core and carry a current of $2A$. If the number turns is $1000permeter$, calculate the intensity of magnetization.

• A. $2\times {10}^{3}A/m$
• B. $4\times {10}^{4}A/m$
• C. $7.93\times {10}^{5}A/m$
• D. $7.93\times {10}^{-5}A/m$

Answer 1

The correct option is C $7.93\times {10}^{5}A/m$

Given:

${\mu }_r=400$

$i=2A$

$n=1000\text{per metre}$

Solution :

Intensity of magnetization is given as : $I=\frac{B}{{\mu }_0}-H$

So, $H=n\times i=1000\times 2=2000A{m}^{-1}$

And, $B=\mu ni={\mu }_r{\mu }_{0}ni$

$B=400\times (4\pi \times {10}^{-7})\times 1000\times 2$

$B=32\pi \times {10}^{-2}T$

So, $I=\frac{32\pi \times {10}^{-2}}{4\pi \times {10}^{-7}}-2000A{m}^{-1}$

So, $I=800000-2000=798000=7.98\times {10}^5$

This is close to option C.

So Correct opt:[C}