Question

The magnetic moment of a magnet of length $10cm$ and pole strength $4.0Am$ will be:

• A. $0.4A{m}^2$
• B. $1.6A{m}^2$
• C. $20A{m}^2$
• D. $8.0A{m}^2$

Answer 1

Answer: (A)

The magnetic moment or magnetic dipole moment is a measure of the strength of a magnetic source. The magnetic moment is denned as pole strength multiplied by the distance between the poles,
$M=m\times 2l$
Given, $2l=10cm=10\times {10}^{-2}m,m=4A-m$
$\therefore$ $M=0.10\times 4=0.4A-m^2$
Note: Magnetic moment is a vector quantity pointing along the axis of the magnet from $S$ to $N$.