Respuesta :

The answer is D. A universal motor uses brushes made out of carbon. The softness of the carbon allows easy direct radial contact with the communicator without any damage. It also allows easy reversal of rotor direction. A carbon brush has a flexible copper jumper lead attached.

Answer:

d. carbon.

Explanation:

A universal motor is a motor that is able to work with direct and altern current, this means that no matter what kind of current they are using the motor will work the same, in its functioning it uses carbon brushes which are cheaper and because of that they wear more easily and cause the universal motor to be used only in appliances that aren´t commonly used for long periods of time.