Question

The effective length of a magnet is 31.4 cm and its pole strength is 0.5 Am. The magnetic moment, if it is bent in the form of a semicircle will be

• A. $0.1A{m}^2$
• B. $0.01A{m}^2$
• C. $0.2A{m}^2$
• D. $1.2A{m}^2$

Answer 1

The correct option is A $0.1A{m}^2$

Similar to solution (1)
New magnetic moment
$M^{{}^{\prime }}=\frac{2M}{\pi }=\frac{2mL}{\pi }=\frac{2\times 0.5\times 31.4\times {10}^{-2}}{3.14}=0.1amp\times m^2$