A/C, D/C, and Magnetism - Part 3

If the peak-to-peak voltage is 240V the peak voltage is

120 V

When current rises and falls at the same rate as the voltage and reverses the direction of flow when the voltage reverses polarity, the current is said to be _____ with the voltage.

In phase

The speed regulation of a DC motor is proportional to the _____.

Armature resistance

In a compound DC motor control circuit, the field loss relay will disconnect the _____ if power is lost to the _____.

Armature, shunt field

The relationship of the strengths of the two fields in a generator determines the amount of _____.

Compounding

Each complete waveform of 360° is called a _____.

Cycle

The compound motor connection that should generally be avoided is the _____.

Differential

The unit of frequency is _____.

Hertz

Permanent magnet motors have _____ efficiency than conventional field-wound motors.

Higher

A series motor may be operated with no load connected.

True

A triangle wave is waveform in which voltage rises at a constant rate with respect to time.

True

The unit of measure of the power delivered to the load in a DC circuit is _____.

Watts

A transformer that has one winding, which is used for both the primary and secondary, is called a(n) _____.

Autotransformer

A generator containing both series and shunt fields is called a _____ generator.

Compound

A wave in which the voltage rises at a constant rate with respect to time is a _____ wave.

Linear

A device that converts electrical energy into mechanical energy is called a(n) _____.

Motor

Square waves are generally produced by electronic devices called _____.

Oscillators

Shunt generators contain only a shunt field winding connected in _____ with the armature.

Parallel

The maximum point of a waveform is called the _____.

Peak

_____ is the square root of the mean of the square of the instantaneous currents.

RMS

A(n) _____ load contains pure resistance.

Resistive

A compound motor has _____ field windings.

Series and shunts

The DC motor, known as a "constant speed motor," is the _____ motor.

Shunt

When the field winding of a DC motor is connected in parallel with the armature, the motor is called a _____ motor.

Shunt

When a motor is connected differential compound, the _____ determines the direction of rotation of the motor at no load or light load.

Shunt field

Rotating machines normally produce a waveform called a _____ wave.

Sine

The most common of all AC waveforms is the _____ wave.

Sine

The_____ effect occurs when AC induces eddy currents into the conductor, which cause the electrons to be repelled toward the outer surface of the conductor.

Skin

Counter-electromotive force (CEMF) and back-EMF are names for the voltage induced into the armature of a DC motor.

True

The amplitude of a waveform is measured from _____.

zero to the highest value obtained in either direction

The output voltage of a generator is usually controlled by the amount of _____.

Field excitation current

The number of cycles completed in one second is called a _____.

Frequency