Practice # 10 AC & DC Motors

Front

What is the armature assembly in a DC motor?

Back

The armature assembly contains a laminated, soft-iron core, coils, and a commutator, all mounted on a rotatable steel shaft.

Front

What information does the data plate on an AC motor provide?

Back

The data plate usually gives the number of poles and the speed at which the motor is designed to run.

Front

How are eddy current losses reduced in motors?

Back

Eddy current losses are reduced by laminating the field poles, frame, and armature.

Front

What does an AC-series motor resemble?

Back

An AC-series motor resembles a DC motor in that it has brushes and a commutator.

Front

What is another name for a three-phase AC induction motor?

Back

The three-phase AC induction motor is also called a squirrel cage motor.

Front

Define a DC motor.

Back

A DC motor is an electric motor that runs on direct current (DC) electricity, converting electrical energy into mechanical energy.

Front

What is the function of a commutator in a DC motor?

Back

The commutator reverses the direction of current flow through the armature windings, allowing for continuous rotation.

Front

What is the role of field assembly in a DC motor?

Back

The field assembly generates a magnetic field that interacts with the armature to produce torque.

Front

Explain the difference between induction and synchronous motors.

Back

Induction motors operate on the principle of electromagnetic induction, while synchronous motors operate at a constant speed synchronized with the supply frequency.

Front

What is a starting capacitor in an AC motor?

Back

A starting capacitor provides an initial boost of energy to start the motor, improving its starting torque.