On the Eastern sections of the Historic Columbia River Highway between Hood River and The Dalles the hillsides are now green in their sublime spring beauty. Wildflowers and wild grasses abound. Get out there in early spring, because the eastern Columbia River Gorge landscape is usually brown by the middle of May.
Magneto Motive Force is expressed as a current, I flowing through a coil of N turns. The magnetic field strength of an electromagnet is therefore determined by the ampere turns of the coil with the more turns of wire in the coil the greater will be the strength of the magnetic field.
With a little effort, you will find the field strength to be roughly 2.35 Teslas. So for hydrogen, a static magnetic field strength of 2.35T yields an NMR frequency of 100MHz. A 4.70T field will result in an NMR frequency of 200MHz. In other words, the NMR frequency is proportional to the magnetic field strength.