A typical size universal motor used in an appliance requires ____________ replacement after 200 to 1200 hours of service.

The correct choice highlights the component commonly needing replacement in universal motors due to their operational characteristics. Universal motors, found in many household appliances, rely on carbon brushes to conduct electrical current to the rotating part of the motor, known as the rotor. Over time, these brushes wear down because they are in constant frictional contact with the rotor's commutator.

As the motor runs, the brushes gradually degrade, leading to diminished performance, such as reduced torque or uneven rotations. The lifespan of carbon brushes typically ranges from 200 to 1200 hours, making them a critical maintenance item for universal motor operation. Regular inspection and timely replacement of the carbon brushes are essential to maintaining the efficiency and longevity of the motor.

While bearings, capacitors, and gears are also essential components of various motors and appliances, they do not typically have the same wear issues as carbon brushes in the context of a universal motor’s operational life. Therefore, the focus on carbon brushes is key when discussing routine maintenance and component failures in these motors.