What is the function of slip ring contact brushes of an AC generator and split rings brushes of electric motors?

Hint: In order to answer this question we will look at the differences of A.C generator and electric motor. We will also look at the parts mentioned in the question and also the function carried out by each of the parts of A.C generator and electric motor. And at last we will compare between the slip rings of an AC generator and split rings of an electric motor.

Complete answer:
The AC generator converts mechanical energy into electrical energy and the electric motor on the other hand converts electrical energy into mechanical energy.Let us look at the 2 parts of AC generator (slip ring and contact brush):

Slip rings: slip ring is a semi-circle shaped electrochemical device used to rotate a coil in the generator. The main function of these slip rings is to transmit electric power into a coil which is at rest to make it move or particularly rotate it.
Contact brushes: a carbon brush is connected to the slip rings. It helps to transmit electric current received from the slip rings further into the circuit.

Now about DC motor:
Split rings: it is also called a commutator. It helps to keep the coil rotating by varying the magnetic fields. The split rings continuously reverse the direction of current to maintain a certain torque so that the coil keeps rotating.
Carbon brushes: it ensures spark free transmission and reduces the damage of the motor by carrying the current to and fro.

Note: let's look at the differences of slip ring and split ring: the slip ring is mainly used to transmit power between static coil and the rotating coil . The split rings on the other hand, reverses the direction of current.