Magnetic Field and Earth's Magnetism — Chapter Summary

A current

A current-carrying solenoid, coil, or loop behaves like a bar magnet. A planar loop has magnetic dipole moment m = IA, and for N turns m = NIA. The di

Magnetic dipole moment is a vector

Magnetic dipole moment is a vector quantity with SI unit ampere-metre squared (A-m²) and dimensions [AL²]. It measures the strength and orientation of

An electron in circular motion forms

An electron in circular motion forms a tiny current loop. Its magnetic moment is m = evr/2. Since orbital angular momentum is J = mevr, the ratio m/J

For the hydrogen atom in

For the hydrogen atom in the lowest orbit, the magnetic moment of the revolving electron becomes 9.27×10^-24 A-m². This is the minimum value of the el

At the axial point

At the axial point, B = (μ0/4π) × 2mr/(r²-l²)², and for a small magnet B = (μ0/4π) × 2m/r³. On the equatorial line, B = (μ0/4π) × m/(r²+l²)^(3/2), and