Question

1) why carbon brushes is used in the commutator ?​

Answer 1

A carbon brush is a critical part of a dc motor, which relies on the brush for the transmission of electrical current coming from the machine's rotating part. ... Thus, this prevents the motor, or commutator, from wearing out. This barrier is why the commutator maintains its smoothness and optimal condition.

Answer 2

Answer:

Friction between the segments and the brushes eventually causes wear to both surfaces. Carbon brushes, being made of a softer material, wear faster and may be designed to be replaced easily without dismantling the machine.