NAVEDTRA 14177A, NEETS, MODULE 05 -- GENERATORS AND MOTORS

Card Set Information

Author:
david11090
ID:
232174
Filename:
NAVEDTRA 14177A, NEETS, MODULE 05 -- GENERATORS AND MOTORS
Updated:
2013-08-31 16:38:51
Tags:
GENERATORS MOTORS
Folders:

Description:
quiz one of one
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user david11090 on FreezingBlue Flashcards. What would you like to do?


  1. In a two-phase motor stator, what is the angular displacement between the field poles?



    • 


    • 
    180º

    • 
    90º
    • 
    360º
    90º
  2. Under which of the following conditions does sparking occur between the brushes and the commutator?



    • 
    When operating under normal conditions

    • 
    When there is an excessive load current

    • 
    When commutation is in the neutral plane (your response)

    • 
    When there is improper commutation
    When there is improper commutation
  3. Which of the following is NOT a major classification of dc generators?



    • 
    Lap-wound (correct answer)

    • 
    Series-wound

    • 
    Compound-wound
    • 
    Shunt-wound
    Compound-wound
  4. What special-purpose dc generator is used as a high-gain power amplifier?



    • 
    Amplidyne 

    • 
    Shunt-wound

    • 
    Lap-wound

    • 
    Compound-connected
    Amplidyne
  5. The current in the interpoles of a dc motor is the same as the



    • 
    eddy current

    • 
    field current

    • 
    armature current 

    • 
    total load current
    armature current 
  6. How can the direction of rotation be changed in a dc motor?



    • 
    Only by reversing the field connections

    • 
    By reversing both the armature connections and the field connections

    • 
    Only by reversing the armature connections

    • 
    By reversing either the armature connections or the field connections
    By reversing either the armature connections or the field connections
  7. The ac power aboard ship is usually distributed as what voltage?



    • 
    115-volt, three-phase

    • 
    230-volt, single-phase

    • 
    115-volt, single-phase

    • 
    450-volt, three-phase
    450-volt, three-phase
  8. In alternators with low-speed prime movers, only what type of rotor may be used?



    • 
    Armature

    • 
    Turbine-driven

    • 
    Geared

    • 
    Salient-pole
    Salient-pole
  9. What does the term single-phase mean relative to single-phase alternators?



    • 
    Only one voltage is produced 

    • 
    The voltage and current are in phase

    • 
    All output voltages are in phase with each other

    • 
    The phase angle is constant
    Only one voltage is produced
  10. Eddy currents in armature cores are kept low by which of the following actions?



    • 
    Using powdered iron as a core material

    • 
    Laminating the iron in the core
    • 
    Insulating the core

    • 
    Limiting armature current
    Laminating the iron in the core
  11. What term applies to the difference between the speed of the rotating stator field and the rotor speed?



    • 
    Slip
    • 
    Rotor error

    • 
    Torque

    • 
    Synchronous
    Slip
  12. What determines the direction of rotation of a dc motor?



    • 
    The number of armature coils

    • 
    The method of excitation

    • 
    The polarity of armature current and direction of magnetic flux 

    • 
    The type of armature
    The polarity of armature current and direction of magnetic flux 
  13. What is the load on a dc motor?



    • 
    The total current drawn from the source

    • 
    The armature current

    • 
    The field current

    • 
    The mechanical device the motor moves
    The mechanical device the motor moves
  14. When a series dc motor is operated without a load, which of the following conditions occurs?



    • 
    The armature draws excessive current

    • 
    The armature will not turn

    • 
    The armature speeds out of control

    • 
    The voltage requirement increases
    The armature speeds out of control
  15. Magnetic induction in an alternator is a result of relative motion between what two elements?



    • 
    The field and the stator

    • 
    The armature and the field 

    • 
    The rotor and the field

    • 
    The rotor and the armature
    The armature and the field 
  16. When two adjacent segments of the commutator on a single-loop dc generator come in contact with the brush at the same time, which of the following conditions will occur?



    • 
    The output voltage will be zero
    • 
    The output voltage will be maximum negative

    • 
    The output voltage will be maximum positive
    The output voltage will be zero
  17. What type of ac motor is the simplest and least expensive to manufacture?



    • 
    Synchronous

    • 
    Two-phase

    •  

    Induction
    • 
    Series
    Induction
  18. In a single-phase alternator with multiple armature windings, how must the windings be connected?



    • 
    Parallel

    • 
    Delta

    • 
    Series 

    • 
    Wye
    Series
  19. When you use the left-hand rule for generators, what is indicated by the middle finger?



    • 
    Direction of the magnetic field

    • 
    Direction of flux

    • 
    Direction of current flow 

    • 
    Direction of motion
    Direction of current flow
  20. In a dc motor, what causes counter emf?



    • 
    Improper commutation

    • 
    Generator action
    • 
    Excessive speed

    • 
    Armature reaction
    Generator action
  21. In generators, what principle is used to convert mechanical motion to electrical energy?



    • 
    Magnetic repulsion

    • 
    Atomic reaction

    • 
    Magnetic induction

    • 
    Electrical attraction
    Magnetic induction
  22. Distortion of the main field by interaction with the armature field can be compensated for by the use of



    • 
    slip rings

    • 
    interpoles 

    • 
    special brushes

    • 
    a commutator
    interpoles
  23. In most alternators, the output voltage is controlled by adjusting the



    • 
    rotor speed

    • 
    electric load

    • 
    field voltage

    • 
    armature resistance
    field voltage
  24. In an elementary, single-coil, dc generator with one pair of poles, what is the maximum number of pulsations produced in one revolution?



    • 
    One

    • 
    Two 

    • 
    Three

    • 
    Four
    Two
  25. Adjacent phase windings of a 3-phase motor stator are what total number of degrees apart?



    • 
    90º

    • 
    30º

    • 
    120º 

    • 
    180º
    120º
  26. In a dc motor, the neutral plane shifts in what direction as the result of armature reaction?



    • 
    Opposite the direction of rotation

    • 
    Counterclockwise

    • 
    Clockwise

    • 
    In the direction of rotation
    In the direction of rotation
  27. The number of pole pairs required to establish a rotating magnetic field in a multiphase motor stator is determined by which of the following factors?



    • 
    The magnitude of the voltage

    • 
    The magnitude of the current

    • 
    The size of the motor

    • 
    The number of phases
    The number of phases
  28. What components cause(s) a generator to produce a dc voltage instead of an ac voltage at its output?



    • 
    The brushes

    • 
    The commutator
    • 
    The armature

    • 
    The slip rings
    The commutator
  29. Which, if any, of the following situations is a major electrical difference between a dc motor and a dc generator?



    • 
    The armatures are different

    • 
    The shunt connections are different

    • 
    The dc generator requires a commutator, the dc motor does not

    • 
    None of the above
    None of the above
  30. What type of ac motor is most widely used?



    • 
    Series

    • 
    Universal

    • 
    Synchronous

    • 
    Single-phase induction
    Single-phase induction
  31. The maximum gain possible from an amplidyne is approximately



    • 
    10,000 

    • 
    50,000

    • 
    100

    • 
    5,000
    10,000
  32. Which of the following types of motors is widely used to power small appliances?



    • 
    Compound

    • 
    Universal

    • 
    Synchronous

    • 
    Polyphase
    Universal
  33. A universal motor is a special type of



    • 
    series motor 

    • 
    parallel motor

    • 
    synchronous motor

    • 
    polyphase motor
    series motor
  34. Which of the following types of motors has a constant speed from no load to full load?



    • 
    Universal

    • 
    Synchronous 

    • 
    Induction

    • 
    Series
    Synchronous
  35. How can you vary the strength of the magnetic field in a dc generator?



    • 
    By varying the speed of armature rotation

    • 
    By varying the voltage applied to the electromagnetic field coils 

    • 
    By varying the armature current

    • 
    By varying the polarity of the field poles
    By varying the voltage applied to the electromagnetic field coils 
  36. What type of dc generator application best utilizes the features of the lapwound armature?



    • 
    High-voltage

    • 
    High-current 

    • 
    High-speed

    • 
    Variable-speed
    High-current
  37. When you use the right-hand rule for motors, what quantity is indicated by the extended forefinger?



    • 
    Direction of motion

    • 
    Direction of current

    • 
    Direction of flux south to north

    • 
    Direction of flux north to south
    Direction of flux north to south
  38. The speed of the rotor of an induction motor depends upon which of the following factors?



    • 
    The method of connecting the load

    • 
    The torque requirements of the load 

    • 
    The current in the rotor

    • 
    The dc voltage applied to the rotor
    The torque requirements of the load
  39. The output frequency of an alternator is determined by what two factors?



    • 
    The number of poles and the number of phases

    • 
    The speed of rotation and the voltampere rating

    • 
    The number of phases and the voltampere rating

    • 
    The number of poles and the speed of rotation
    The number of poles and the speed of rotation
  40. In a dc motor, what is the purpose of the resistor placed in series with the armature?



    • 
    To prevent overspeeding

    • 
    To increase field strength

    • 
    To counteract armature reaction

    • 
    To limit armature current
    To limit armature current
  41. Alternators are rated using which of the following terms?



    • 
    Amperes

    • 
    Volts
    • 
    Volt-amperes

    • 
    Watts
    Volts
  42. Distortion of the main field by interaction with the armature field defines what term?



    • 
    Mutual induction

    • 
    Mutual reaction

    • 
    Armature reaction

    • 
    Commutation
    Armature reaction
  43. As the load current of a dc generator varies from no-load to full-load, the variation in output voltage is expressed as a percent of the full-load voltage. What term applies to this expression?



    • 
    Load limit

    • 
    Voltage regulation

    • 
    Voltage control

    • 
    Gain
    Voltage regulation
  44. What characteristic of series-wound generators makes them unsuitable for most applications?



    • 
    They are not capable of supplying heavy loads

    • 
    They require external field excitation

    • 
    The output voltage varies as the load current varies 

    • 
    The output voltage varies as the speed varies
    The output voltage varies as the load current varies
  45. A dc series motor is best suited for which of the following applications?



    • 
    Steady load, high torque

    • 
    Variable load, high torque 

    • 
    Variable load, low torque

    • 
    Steady load, low torque
    Variable load, high torque
  46. When two or more generators are used to supply a common load, what term is applied to this method of operation?



    • 
    Series

    • 
    Split-load

    • 
    Compound

    • 
    Parallel
    Parallel
  47. Why are shaded-pole motors built only in small sizes?



    • 
    They have weak starting torque

    • 
    They require large starting current

    • 
    They are unidirectional

    • 
    They are expensive in large sizes
    They have weak starting torque
  48. When the voltage applied to the armature of a dc shunt motor is decreased, what happens to the motor speed?



    • 
    It increases

    • 
    It decreases

    • 
    The motor stops

    • 
    It becomes uncontrollable
    It decreases
  49. In a dc motor, how, if at all, does counter emf affect speed?



    • 
    It causes the speed to decrease

    • 
    It does not affect speed 

    • 
    It causes the speed to increase

    • 
    It causes rapid fluctuations of the speed
    It does not affect speed
  50. An elementary generator consists of a single coil rotating in a magnetic field. Why is NO voltage induced in the coil as it passes through the neutral plane?



    • 
    Flux lines are too dense

    • 
    Flux lines are not being cut 

    • 
    Flux lines are not present

    • 
    Flux lines are being cut in the wrong direction
    Flux lines are not being cut
  51. What are the two basic types of alternators?



    • 
    Multiphase and polyphase

    • 
    Alternating current and direct current

    • 
    Series-wound and shunt-wound

    • 
    Rotating field and rotating armature
    Rotating field and rotating armature
  52. The gain of an amplifying device can be determined by which of the following formulas?



    • 
    GAIN = OUTPUT / INPUT
    • 
    GAIN = OUTPUT- INPUT

    • 
    GAIN = INPUT + OUTPUT

    • 
    GAIN = INPUT *OUTPUT
    GAIN = OUTPUT / INPUT
  53. The output voltage of an elementary generator is coupled from the armature to the brushes by what devices?



    • 
    Interpoles

    • 
    Terminals

    • 
    Pigtails

    • 
    Slip rings
    Slip rings
  54. Voltage is induced in what part of an alternator?



    • 
    The brushes

    • 
    The armature

    • 
    The field

    • 
    The commutator
    The armature
  55. An alternator using a gas turbine as a prime mover should have what type of rotor?



    • 
    Armature

    • 
    Geared

    • 
    Turbine-driven

    • 
    Salient-pole
    Turbine-driven
  56. What is the main advantage of a shunt motor over a series motor?



    • 
    A shunt motor draws less current from the source than a series motor

    • 
    A shunt motor develops higher torque at lower speeds than a series motor

    • 
    A shunt motor maintains a more constant speed under varying load conditions than a series motor

    • 
    A shunt motor can be operated at higher speeds than a series motor
    A shunt motor maintains a more constant speed under varying load conditions than a series motor
  57. What is the phase relationship between the output voltages of a three-phase alternator?



    • 
    In phase

    • 
    120ºout of phase

    • 
    90ºout of phase

    • 
    60ºout of phase
    120ºout of phase
  58. Motor reaction in a dc generator is a physical force caused by the magnetic interaction between the armature and the field. What effect, if any, does this force have on the operation of the generator?



    • 
    It tends to oppose the rotation of the armature 

    • 
    It tends to aid the rotation of the armature

    • 
    It causes the generator to vibrate

    • 
    None
    It tends to oppose the rotation of the armature
  59. What type of ac motor uses a combination of inductance and capacitance to apply out-of-phase currents to the start windings?



    • 
    Synchronous

    • 
    Series

    • 
    Split-phase induction

    • 
    Three-phase
    Split-phase induction
  60. Which of the following motors is/are types of ac motor?



    • 
    Series

    • 
    Synchronous

    • 
    Induction

    • 
    All of the above
    All of the above

What would you like to do?

Home > Flashcards > Print Preview