Practice portal › Magnetism and Matter › Bar Magnet and Dipole in a Field
Asked in GUJCET 2019 · Magnetic moment of magnets and loops
Idea: an electron in a circular orbit of radius r and speed v is a tiny current loop. Its orbital magnetic moment is μₗ=(evr)/2 and its orbital angular momentum is l=mₑ v r.
The gyromagnetic ratio is the ratio of these two: (μₗ)/l=(evr/2)/(mₑ v r)=e/(2mₑ).
The specific charge of the electron is e/(mₑ).
So (μₗ)/l=1/2×e/(mₑ): the gyromagnetic ratio is half the specific charge.
In numbers, e/(2mₑ)=8.8×10¹⁰ C kg⁻¹ against e/(mₑ)=1.76×10¹¹ C kg⁻¹.
Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.
Practise this with a timer