Electrical 10

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

armature, shunt field

In a series DC generator, if load is added, the current flow ___ and the output voltage ___

increases, increases

In a DC generator, the three main basic typs of armature windings are the

lap-wound, the wire-wound and the frog leg-wound

What tool is commonly used to set the neutral plane of a DC generator?

AC Voltmeter

T/F It is all right to operate series motor with no load connected

FALSE

The servomotor which has a fiberglass and copper rotor is the ___ motor

ServoDisc

In a DC generator, when more loops of wire are used in the armature, this results in less ripple of the rectified voltage

TRUE

The cumulative compound motor connection means that the fields of the series and shunt field windings

add

Armature reaction is the bending of the line of flux between the pole pieces by the magnetic field produced around the

armature

Countertorque is caused by the magnetic attraction between the field pole pieces and the ___ magnetic field

armature

When the series and shunt field windings of a DC compound generator are connected so they aid each other in the production of magnetism, this is called a ___ compound

cumulative

The compound motor connection that is rarely used is the

differential

In a DC machine, series filed winding are made with relatively ___ turns of ___ wire

few, large

In a DC generator, armatures are wound to provide high voltage, high current, or some specific combination of voltage and current. Which winding type provides moderate voltage and moderate current?

frogleg

In a DC generator, what devices provide the magnetic field necessary for the operation of the machine?

pole pieces

What is the purpose of an equalizer connection in paralleled DC generators?

prevents the motoring of one machine

Because the rotor of a ServoDisc motor is made from copper laminated onto a fiberglass disk, the motor is also called a ___ motor

printed circuit

Some DC servomotors have square wave input voltage. To vary the motor speed, the on and off time ratio of the square wave is varied. This is called ___ modulation

pulse-width

The excitation in a self-excited shunt generator comes from

residual magnetism in the pole pieces

Torque is a force that tends to cause

rotation

In a series-connected DC generator, the field is generated from

self-excitation

A compound motor has ___ field windings

series and shunt

In a DC generator, voltage regulation is determined by the resistance of the armature. A generator with good voltage regulation has a(n) ___ amount of voltage drop as load is added

small

A force that tends to cause rotation is known as

torque

Permanent magnet motors have ___ efficiency than wound field motors

higher

In a DC generator, armatures are wound to provide high voltage, high current, or some specific combination of voltage and current. Which winding type provides high voltage and low current?

wave

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

TRUE

T/F In a DC generator, to increase the amount of output voltage, it is common practice to increae the number of turns of wire for each loop

TRUE

In a DC generator, the rotating member of the machine is called the

armature

The speed regulation of a DC motor is proportional to the

armature resistance

What device, which rides against the commutator segments, carries the power to the outside circuit?

brush

What devices ride against the commutator segments to make an electrical connection to the external circuit of the DC generator?

brushes

The motor that does not contain a wound armature, commutator, or brushes is the ___ motor

brushless DC

In a separated excited DC shunt generator, how is the output voltage controlled?

by varying the field excitation current

In a DC generator, alternating voltage produced in the armature is converted into direct voltage before it leaves the generator by the

commutator

A DC generator containing both series and shunt field windings is called a ___ generator

compound

In a DC compound generator, the relationship of the strength between the series field and the shunt field windings determines the amount of

compounding

A device that converts mechanical energy into electric energy in the form of DC is called a(n)

generator

In a DC generator, armatures are wound to provide high voltage, high current, or some specific combination of voltage and current. Which winding type provides low voltage and high current?

lap

DC generators operate on the principle of ___ induciton

magnetic

A DC generator that uses permanent magnets as its field is commonly referred to as a

magneto

In a DC machine, shunt field windings are made with ___ turns of ___ wire

many, small

A device that converts electrical input into mechanical output is called

motor

Small permanent magnet motors that have lightweight rotors are often used as

servomotors

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

T/F When the windings in a DC generator are perpendicular to the lines of flux, and maximum induced voltage is being created, this is usually called the neutral plane

FALSE

In a DC compound generator, the series field diverter is also called the

series field shunt rheostat