In reality, protons are not __, but instead are __, which generate a small __ that opposes the externally applied field.
In a molecule the electron clound around each nucleus acts like a loop of wire, rotating in response to teh external field. This induced rotation is a __ whose magnetic field opposes the __. The result is that the magnetic field at the nucleus is weaker than the external field., and we say that the nucleus is __.
The effective magnetic field __ is always weaker than the external field, so the applied field must be increased for resonance to occur at a given frequency.
- surrounded by electrons that partially shield them from the external magnetic field
- induced magnetic field
- circular current
- external field
- at the shielded proton