Nuclear Magnetic Resonance Spectroscopy:
The energy separation between the different nuclear spin states lies in the microwave spectral region and hence NMR transitions are excited by frequencies about 108 Hz and can be varied by applying a magnetic field.
The nucleus has a positive change and is spinning, resulting in a small magnetic field. As a result, the nucleus possesses a magnetic moment, which is proportional to its spin, I.
The constant g is gyromagnetic ratio. The energy of a particular energy level is defined as
where B is the strength of the magnetic field at the nucleus.
Therefore, the difference in energy levels can be obtained in the form of
This equation suggests that if the magnetic field B is increased, then the difference in the energy also increases.