Why are split rings used in a motor?

Why do we use the F.L.H. Rule?

What does Lenz's law state?

What is the deflection of the galvanometer when:
a) A magnet enters the solenoid north pole facing the solenoid?
b) A magnet leaves the solenoid north pole facing the solenoid?
c) A magnet leaves the solenoid south pole facing the solenoid?

List three ways you would increase the speed of a motor?