Exam 17: Dc Motors

In a brushless DC motor, a special circuit is used to perform the commutation of the applied DC.

An instrument designed to measure torque is called a ____ .

____ motors are designed to be used for jobs requiring minimum torque.

The operation of a motor depends upon the interaction between ____ magnetic fields.

Because the armature of a DC motor is wound in much the same way as a DC generator, the current from the supply must divide and flow through three or more paths.

A good commutator will have a very dark brown film of oxide.

A ____ motor has a very high starting torque.

Arcing at the brushes may be the result of _____.

In some types of DC motor arrangements, a flywheel assists the motor in driving the load.

When using the right hand rule for a motor, the thumb points in the direction of the ____.

The starting torque of a shunt motor is about ____ times the full-load torque.

Insulation tests are a type of motor maintenance task that should be performed on a regular basis.

One application of a phototransistor is a(n) _____.

A(n) ____ is a type of rotating switch.

Overheated bearings may be the result of _____.