Deck 14: Direct Current Generators

Question 1

When a load is connected to the output of a compound generator, the initial voltage produced by the residual magnetism of the pole pieces produces a current flow through the load.

Answer 1

False

Question 2

Field ____ current is the DC current that flows through the shunt field winding.

A) relaxation
B) hesitation
C) resistance
D) excitation

Answer 2

D

Question 3

Armature reaction can be corrected by rotating the brushes an amount ____ the shift of the neutral plane.

A) just less than
B) slightly greater than
C) equal to
D) double the amount of

Answer 3

C

Question 4

The amount of output voltage produced by a generator is proportional to three factors, including the number of turns of wire in the armature, the strength of the magnetic field of the pole pieces, and the speed of the cutting action (speed of rotation).

Question 5

____ left-hand generator rule can be used to determine the relationship of the motion of the conductor in a magnetic field to the direction of the induced current.

A) Phillip's
B) Fulton's
C) Fleming's
D) Fielding's

Question 6

Wave wound armatures are used in machines designed for ____.

A) low voltage and low current
B) low voltage and high current
C) high voltage and high current
D) high voltage and low current

Question 7

To increase the amount of output voltage, it is common practice to increase the number of turns of wire for each loop. If a loop contains 20 turns of wire, the induced voltage will be 40 times greater than that for a single-loop conductor.

Question 8

Countertorque is a measure of the useful electrical energy produced by a generator.

Question 9

When more than one loop is used, the average output voltage is higher and there is less pulsation of the rectified voltage. This pulsation is called ____.

A) curling
B) wave
C) ripple
D) bubbling

Question 10

There may be occasions when one direct current generator cannot supply enough current to operate the connected load. In such a case, another generator is connected in parallel with the first. Direct current generators should never be connected in parallel without an equalizer connection.

Question 11

The three basic types of armature windings are the lap, wipple, and dogleg.

Question 12

The amount of compounding in a DC machine is controlled by connecting a high-value variable resistor in parallel with the series field.

Question 13

In the left-hand rule, the center finger shows the direction of the ____.

A) thrust
B) current induced into the armature
C) movement of the conductor
D) field flux

Question 14

A(n) ____ compound generator has its fields connected in such a manner that they oppose each other in the production of magnetism.

A) oppositional
B) differential
C) cumulative
D) diametric

Question 15

The voltage produced in all rotating commutators is alternating voltage.

Question 16

Lap wound armatures are generally constructed with large wire because of high current.

Question 17

A generator is a device that converts ____ energy into electrical energy.

A) chemical
B) mechanical
C) kinetic
D) physical

Question 18

____ is characterized by the fact that the output voltage at full load will be greater than the output voltage at no load.

A) Over-compounding
B) Alternate compounding
C) Flat compounding
D) Under-compounding

Question 19

One advantage of interpoles is that they restore the field outside their immediate area and are able to overcome all the field distortion.

Question 20

There are three basic types of direct current generators: the series, ____, and compound.

A) shunt
B) frogleg
C) simple
D) open