Question

The magnetic moment associated with a circular coil of $35$ turns and radius $25cm$, if it carries a current of $11A$ is

• A. $72.2A{m}^2$
• B. $70.5A{m}^2$
• C. $74.56A{m}^2$
• D. $75.56A{m}^2$

Answer 1

Answer: (D)

Given $N=35$,
$r=25cm$
$=25\times 10^{-2}m$,
$I=11A$
Then magnetic moment associated with this circular coil
$M=NIA=NI\pi r^2=35\times 11\times 3.14\times {\left(25\times 10^{-2}\right)}^2$
$=75.56A{m}^2$