Question

A solenoid of cross-sectional area $2\times {10}^{-4}{m}^2$ and $900$ turns has $0.6$ $A{m}^2$ magnetic moment. Then the current flowing through it is?

• A. $2.24A$
• B. $2.34mA$
• C. $3.33A$
• D. $3.33mA$

Answer 1

The correct option is C $3.33A$

Here, $N=900$ turns,
$A=2\times {10}^{-4}{m}^2$, $m_s=0.6$A $m^2$
The magnetic moment of solenoid
$m_s=NIA$
The current flowing through the solenoid is
$I=\frac{m_s}{NA}=\frac{0.6}{900\times 2\times {10}^{-4}}=3.33$A
Hence, the correct option is $\left(C\right)$