I want to know the answer to the following question:
The gyromagnetic ratio is the constant proportion between the magentic field and what?
All the background I'm provided with is that "The protons are said to be "shielded" from the applied magnetic field by the electrons in the water molecule, the same effect that gives rise to chemical shift in NMR spectroscopy, and this is indicated by a prime on the symbol for the gyromagnetic ratio, γ′p.". Is that enough to answer the question?
Answer: no