Q. A circular loop has a radius of $5\ cm$ and it is carrying a current of $0.1\ amp$. Its magnetic moment is
A) $1.32 \times 10^{- 4}amp$ -$m^{2}$
B) $2.62 \times 10^{- 4}amp$ -$m^{2}$
C) $5.25 \times 10^{- 4}amp$ -$m^{2}$
D) $7.85 \times 10^{- 4}amp$ -$m^{2}$
Explanation
(d) $M = iA = 0.1 \times \pi \times (0.05)^{2}$
$= (0.1) \times 3.14 \times 25 \times 10^{- 4} = 7.85 \times 10^{- 4}amp - m^{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.