An electron beam in a vacuum tube is directed at right angles to a magnetic field, so that it travels along a circular path.
Predict the effect on the size and shape of the path that would be produced (separately) by each of the following changes:
a. Increasing the magnetic flux density
b. Reversing the direction of the magnetic field
c. Slowing down the electrons
d. Tilting the beam, so that the electrons have a component of velocity along the magnetic field.