Question

Which of the following must not be done to maintain the magnetic field over the sample uniform in space and time?

(a) Large pole pieces need to be used

(b) Pole faces must be polished

(c) Wide pole gap must be present

(d) Magnets can be permanent or electromagnet

The question was asked in my homework.

The question is from Continuous Wave NMR Spectroscopy in chapter Nuclear Magnetic Resonance Spectrometer of Analytical Instrumentation

Answer 1

The correct answer is (c) Wide pole gap must be present

The explanation: Narrow pole gap must be present to maintain the magnetic field over the sample uniform in space and time. The pole faces must be polished to optical tolerances.