Question

Explain the use of brushes in A.C Generator.

Answer 1

For certain types of electric motors or generators to function, the coils of the rotor must be connected to complete an electrical circuit. To accomplish this, a copper or brass commutator or 'slip rings' are affixed to the shaft, and springs press braided copper wire 'brushes' onto the rings which conduct the current.
also
Carbon brushes are used to conduct electrical current between moving parts and stationary wiring.