Question

A circular loop has a radius $10cm$ and is carrying a current of $0.1A$. Its magnetic moment is ______

• A. $3.14A{m}^2$
• B. $3.14\times {10}^{-1}A{m}^2$
• C. $3.14\times {10}^{-2}A{m}^2$
• D. $3.14\times {10}^{-3}A{m}^2$

Answer 1

The correct option is D $3.14\times {10}^{-3}A{m}^2$

$\begin{array}{c}\in =10cm=10\times {10}^{-2}m\\ m=I\times area\\ m=0.1\times \pi {\in }^2={10}^{{}^{-3}}\pi A{m}^2\end{array}$