Question 24 of 57

A $25cm$ long solenoid has the radius $2cm$ and $500$ turns. It carries a current of $15A$. If it is equivalent to a magnet of the same size and magnetization $\vec{M}\left(\dfrac{Magneticmoment}{volume}\right),$then $\left|\vec{M}\right|$ is:

A$3\pi A{m}^{-1}$B$30000A{m}^{-1}$C$30000\pi A{m}^{-1}$D$300A{m}^{-1}$

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Answer: (B) $30000A{m}^{-1}$

$Volume=Al$

$Magnetization\vec{M}=\dfrac{magneticmonent}{Volume}$

$=\dfrac{\left(No.ofturns\right)\times \left(Current\right)\times Area}{Volume}$

$=\dfrac{NIA}{Al}$

$=\dfrac{NI}{l}$

$=\dfrac{500\times 15\times 100}{25}$

$=60\times 500$

$=30\times {10}^{3}$

$=30000A{m}^{-1}$