## The Nuclear Magnetic Resonance phenomena

According to the Bohr equation,
, we need for inducing a transition towards the high level energy, an
energy quantum^{[1]} with a value of
.

This is a resonance condition, with which is the resonance frequency of the nucleus; the Planck constant divided by and the gyromagnetic ratio.

The resonance frequency of the nucleus, which is also called the Larmor frequency, is then proportional to the ﬁeld value following the equation .

Its range is in the high frequencies: in a ﬁeld of l.4T at the level of a frequency of This corresponds to an ultra short radio wavelength of .