A current of 2 ampere is passed in a coil of radius 0.5 m and number of turns 20. The magnetic moment of the coil is
Answer & explanation
Correct answer: option 4
Magnetic Moment $M = NIA = NI \pi r^2 = 20 \times 2 \times \pi \times 0.5^2 = 31.4 Am^2$