Question

A circular coil of 300 turns and average area carries a current of 15A. Calculate the magnitude of magnetic moment associated with the coil.

Answer 1

Magnetic moment is the magnetic strength and orientation of a magnet or other object that produces a magnetic field. More precisely, the term magnetic moment normally refers to a system's magnetic dipole moment, the component of the magnetic moment that can be represented by an equivalent magnetic dipole: magnetic north and south pole separated by a very small distance.

Complete step by step solution:
According to the question,
Number of turns = 300
Average area of coil = $5 \times {10^{ - 3}}{m^2}$
Current flowing through coil = 15A
Magnetic moment associated with the coil will be = NIA (where N is the number of turns A is the area of coil and I is the current flowing through the coil.)
$\therefore$Magnetic moment = NIA
$\begin{gathered} \Rightarrow M = 300 \times 15 \times (5 \times {10^{ - 3}}) \\\ \Rightarrow M = 22.5A{m^2} \\\ \end{gathered}$

Thus the required magnetic moment associated with the coil is $22.5A{m^2}$

Note: In these types of questions always be careful when doing selection between the area of each turn and total area.