Answer / nikhil s shah

Carbon brushes are used to connect external circuits in a
motor or any other machine to the rotor (moving part of the
machine) through the commutator. You can also say that
these brushes transfer electric current to moving part of
the motor or machine.....

Answer / ajayk

yes reason is commutation
but then .we can also use
metal brushes.why dont we
use then. Reason is 1.carbon
has high resistance which
decreases the time constant
of sparking transients during
commutation,so less sparking
and 2.they are cheap too and
long lasting.

Answer / kj

The other reason is that carbon powder is also a lubricant.
This reduces the wear on the commutator.

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