Question

A closely wound solenoid of $3000$ turns and area of cross section $2\times {10}^{-4}{m}^2$, carrying a current of $6$A is suspended through its centre allowing it to turn in a horizontal plane. The magnetic moment associated with this solenoid is

• A. $1.2J{T}^{-1}$
• B. $2.4J{T}^{-1}$
• C. $3.0J{T}^{-1}$
• D. $3.6J{T}^{-1}$

Answer 1

The correct option is D $3.6J{T}^{-1}$

Here, $N=3000,A=2\times {10}^{-4}{m}^2,I=6A$
$\therefore M=NIA=3000\times 6\times 2\times {10}^{-4}=3.6J{T}^{-1}$