AC/DC FINAL

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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


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