AC/DC FINAL
the torque of a squirrel-cage induction motor will be maximum when the phase angle between the stator and rotor fields is
0*
spilt-phase power system has two voltages that are ___________
90* out of phase
the servomotor that has a fiberglass and copper rotor is the _________ motor
ServoDisc
a device that converts electrical energy into mechanical energy
alternator
__________________ operate on the same principle of electromagnetic induction as DC generators, but they have no commutator
alternators
the component of a DC generator that converts the armature AC into DC is
armature
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 motor that does not contain a wound armature, commutator, or brushes is the _____________ motor
brushless DC
An alternator that has a separate small alternator mounted on the shaft of its rotor is equipped with a(n)
brushless exciter
the universal motor has a wound armature and brushes like an AC motor, as well as an added component the ________________
compensating winding
a generator containing both series and shunt fields is called_____________ generator
compound
the relationship of the strengths of the two fields in a generator determines the amount of
compounding
in the consequent pole motor, if the number of poles is doubled, the motor speed will be
cut in half
frequency of the current in the rotor ___________ as the rotor approaches synchronous speed
decreases
the compound motor connection that should generally be avoided is the
differential
a compound generator has both series and shunt field windings. when those windings are connected so their fields oppose each other in the production of magnetism, that connection is called
differential- compound
an _______________ is used to measure the difference in voltage and frequency between two alternators
diode
the output voltage of a generator is usually controlled by the amount of
field excitation current
armatures are wound to provide high voltage, high current or some specific combination of voltage and current. the winding that provides moderate voltage and moderate current is
frogleg-wound
a single-phase synchronous motor is sometimes referred to as an _________ motor
hystersis
Multispeed fan motors achieve multiple speeds by inserting additional ___ in series with the run winding
inductance
armatures are wound to provide high voltage, high current or some specific combination of voltage and current. the winding that provides low voltage and high current is
lap-wound
the revolving armature type of alternator is capable of ____________ power output and is, therefor, ___________ often used than the revolving field type
less, less
the ServoDisc motor is often called a _________ motor
printed- circuit
the speed of the disc servomotor can be varied by changing the amount of voltage supplied to the armature. the voltage is generally varied using __________
pulse-width
an _____ motor operates on the principle that like magnetic poles repel
repulsion
the rotating part of an alternator is called the ________________
rotor
the _____________________ winding is made of few turns of large wire and is located at the bottom of the stator core
run
The series generator has only a series field, which is connected in _____ with the armature.
series
the DC motor, known as a "constant speed motor" is the __________ motor
series
small permanent magnet motors that have lightweight rotors are often used as ___________
servomotors
in the shaded-pole induction motor, the shading coil acts like a transformer with an _________________ secondary winding
shorted
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
the ____________________ winding is made of many turns of small wire and is locatoed at the top of the stator core
start
the squirrel-cage rotor code letters indicate the shape (type) of rotor bars. different types of bars have a large effect on the _______________ of a motor
starting torque
the set of squirrel-cage bars on the rotor of a synchronous motor is used to start the motor and is known as the _____________
starting, bars
the non- rotating part of an alternator is called the ____________
stator
the output shaft of a stepping motor
steps continuously when power is applied
armatures are wound to provide high voltage, high current or some specific combination of voltage and current. the winding that provides high voltage and low current is
wave-wound
a compound generator has both series and shunt field windings. when those windings are connected so they aid each other in the production of magnetism, that connection is called
cumulative-compound
in a universal motor setting the brushes to the neutral plane can be done by connecting voltage to the armature a voltmeter to the series field, and adjusting the brush position for a _____________ reading on the voltmeter
minimum
the higher power output alternators use a revolving
field
for most squirrel-cage induction motors the typical percent slip is about __________ percent
two to five
the ______ motor can operate on either AC or DC voltage
universal
the direct current that is an input to the alternator's rotor is the _______________ current
excitation
series field windings are connected in series with the armature. they are wound with ____________ turns of fairly _____________ wire
few, large
using an ___________ is one method of preventing induced voltage from becoming excessive
field discharge resistor
a device that converts mechanical energy into DC electrical energy is
generator
in the shaded-pole induction motor, the direction of rotation of the magnetic field is determined by the
magnetic field strength
shunt field windings are connected in parallel with the armature. they are wound with ____________ turns of fairly _____________ wire
many, small
in a universal motor setting the brushes to the neutral plane using compensating winding can be done by connecting voltage to the armature a voltmeter to the compensating winding and adjusting the brush position for a __________ reading on the voltmeter
maximum
a compound motor has _______________ field windings
series and shunt
the wound-rotor induction motor is popular in industry because it has _________________starting torque and ____________ starting current
high, low
permanent magnet motors have ________________ efficiency than conventional field-wound motors
higher
the consequent pole motor is an _______________ speed motor
three
the ___________________ ride against the commutator segments and are used to connect the armature to the external circuit of the DC machine.
brushes
in single-phase motors such as the resistance start induction-run motor, the start winding is disconnected by the ______________
centrifugal switch
the output frequency of an alternator is controlled by the ___________
number of stator poles and rotor rotation speed
the differential selsyn has three stator windings connected in a wye and a rotor made of ____________
one winding
If one alternator does not produce sufficient power to supply a load, another alternator can be connected to the circuit. The second alternator is connected in _____.
parallel
shunt generators contain only a shunt field winding connected in ________________ with the armature
parallel
some motors are constructed so that they will operate on either of two voltages. when they are connected to operate on the lower of the two voltages the windings are connected in
parallel
the direction of magnetic field rotation is known as ___________ rotation
phase
If a piece of machinery needs a replacement motor and will be damaged if the new motor rotates the wrong way, the test equipment needed to test the rotation direction fo the new motor is a
phase rotation meter
some motors are constructed so that they will operate on either of two voltages. when they are connected to operate on the higher of the two voltages the windings are connected in
series
in a generator the _______________ permits part of the current that normally flows through the series field to flow through the resistor
series field shunt rheostat
selsyn motors operate on ___________________ voltage
single- phase
connection to the armature of an alternator is normally done by using
sliprings
When a squirrel-cage motor is first started, the value of the current draw is
smaller than the running current
in a three-phase motor, the speed of rotation of the magnetic field is called the _________ speed
synchronous
a synchronous motor operated with no load and used for power factor correction is sometimes called a ______________
synchronous condenser
In a motor that has a rotating magnetic field, the speed of that magnetic field is referred to as the
synchronous speed