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
