(a)[4]
This method uses two magnetic fields that are superimposed. Describe what each of these magnetic fields does.
(b(i))[1]
The frequency $f$ of the electromagnetic waves emitted by protons during relaxation in an MR scanner is given by the equation $f = 2cB$. Calculate the difference in magnetic flux density for matching points in neighbouring sections.
(b(ii))[2]
Calculate the change in emitted frequency.