Advanced AC/DC Machines Final
35. When a load is placed on a universal motor, the motor speed _____.
decreases
47. Three-phase motors are _____. a. self- starting b. simple in construction c. less expensive than other motor types of the same HP rating d. all of these
all of these
52. Multiple-speed, 3 phase motors are designed to operate at _____ speeds. a. two b. three c. four d. all of these
all of these
6. Protective clothing provides protection from contact with _____. a. sharp objects b. hot equipment c. harmful materials d. all of these
all of these
24. Shaded-pole motors are commonly _____.
1/2 HP or less
27. A single phase, dual-voltage, split phase motor typically is set for ____V.
115/230
48. During one revolution, a rotor completes _____ electrical degrees in a 6-pole motor.
360
78. Which of the following is an application for a DC shunt motor? a. centrifugal pump b. cooling fans c. woodworking machinery d. all of these e. none of these
All of these
66. The primary purpose of the interpoles is to ________.
Help reduce sparking between the commutator and the brushes
71. The advantage of the series configured DC motor is that it can produce _______.
High starting torque
79. Which of the following statements is NOT true of a DC compound motor?
It has two configurations in which it can be connected.
77. Which of the following statements is FALSE about a separately-excited shunt motor?
It requires only one power supply
63. Which of the following is NOT a rule of safe dress around any electric motor? a. wear safety glasses b. remove loose items c. tie up long hair d. all of these e. none of these
None of these
20. A(n) _____ is used in the converter section to convert AC voltage to DC voltage.
SCR
56. To connect a dual-voltage, wye-connected, 3 phase motor for high voltage, connect L1, L2, and L3 to T1, T2, and T3 and use wire nuts to connect _____.
T4 to T7, T5 to T8, and T6 to T9
97. The English units of motor power are _______.
horsepower
74. A DC shunt motor has the field windings connected ______ with the armature.
in parallel
55. In a variable torque motor, torque and horsepower _____ at higher speed and _____ at lower speed.
increases;decreases
58. Electric motors rely on the principle of ________ to convert electrical power into mechanical power.
inductance
25. When a split-phase motor is first connected to power, the _____.
inductive reactance of the start winding is lower
4. A(n) _____ is a meter that takes temperature measurements without touching an object.
infrared meter
51. To reverse the direction of rotation of a delta-connected, 3 phase motor, _____.
interchange T1 and T3
14. A(n) _____ is an electronic device that changes DC voltage into AC voltage.
inverter
80. The primary advantage of a DC compound motor is _____.
it provides high starting torque
19. The voltage of a coil in a magnetic starter is typically _____ the voltage used by the motor.
lower than
89. The S.I. units of torque are ______?
newton meters
43. The armature is the ____ part of a DC motor.
rotating
85. Instruments designed to measure motor speed are called ________.
tachometers
8. The National Electric Code (NEC) is updated every _____ years.
three
2. A(n) _____ is used to indicate if voltage is present in a circuit, but it does not measure the actual voltage amount.
voltage indicator
57. When troubleshooting a 3 phase motor, if the check for open or shorted windings reads _____, the coil is shorted.
zero
30. A ½ HP capacitor motor requires a capacitor with a value of _____uF.
190/260
22. In a split-phase motor, the main winding current lags the applied voltage by about _____%
20
23. A 1725 rpm motor (1800 rpm synchronous speed) has a slip of approximately ____%.
4
21. The starting torque of a split-phase motor is _____% of the full-load torque.
75-200
50. In a dual-voltage, wye-connected, 3 phase motor, _____ terminal leads are available.
9
28. A(n) _____ degree phase difference is required to produce maximum starting torque in a split-phase motor.
90
16. The major difference between AC and DC generators is that DC generators contain _____.
A commutator
72. If a DC series motor is operated without a load, a condition called ______ will occur.
Runaway
29. The industrial standard for reversing the direction of rotation of a single phase motor is _____. a. reversing the starting winding b. reversing the running winding c. all of these d none of these
all of these
39. The DC compound motor has _____. a. a series field b. a shunt field c. has good regulation speed d. all of these
all of these
42. A reversible universal motor may be reversed by _____. a. using one coil for the forward direction and the other for the reverse direction b. reversing the direction of the current in the field c. all of these d. none of these
all of these
62. Which of the following is a category of electric motors? a. Dc motors b. Univerisal motors c. Ac motors d. all of these e. none of these
all of these
68. Which of the following is a wiring configuration for a DC motor? a. series b. shunt c. compound d. all of these
all of these
82. Which of the following is an application of a DC compound motor? a. conveyors b. punch press c. bending machines d. all of these e. none of these
all of these
99. Which of the following is a motor performance characteristic considered when selecting a motor for an application? a. torque output b. efficiency c. speed d. all of these e. none of these
all of these
70. Which of the following is an application of a DC series motor? a. locomotive b. crane c. hoist d. all the above e. none of these
all the above
41. The three terminals of an SCR are the _____.
anode, gate and cathode
65. Which of the following is not a component of a DC motor?
bearings
32. A split-phase motor has a _____ winding. a. starting b. running c. both A & C d. none of the above
both A & C
9. A class _____ fire extinguisher should be used on electrical fires
c
10. _____ is a signal word that is used to indicate a potentially hazardous situation that, if not avoided, may result in a minor or moderate injury.
danger
31. A shaded- pole motor has _____ starting torque
low
5. A(n) _____ is the application of excessive load to a motor.
overload
34. The field of a DC shunt motor is connected in _____ with the armature.
parallel
54. In a constant torque motor, horsepower changes ____ to the speed.
proportionally
98. Motor efficiency is _______.
ratio of output to input
84. The rotational speed of a motor is measured in units of ________.
revolutions per minute
13. A _____ is a motor control device that provides a gradual voltage increase during AC motor starting and a gradual voltage decrease during stopping.
soft starter
59. The ______ is the stationary winding of the electric motor.
stator
11. The stationary magnetic field is called the _____ in AC motors and the _____ in DC motors.
stator;rotor
3. A(n) _____ is an electrical test instrument that indicates the approximate voltage in an electrical circuit.
voltage tester
49. In a single-voltage, delta connected, 3 phase motor, each phase is _____.
wired end to end to form a closed circuit
53. In a constant horsepower motor, torque _____ as speed increases
decreases
18. The four most common methods of motor control include PLC's, electric motor drives, terminal hard wiring, and _____.
direct hand writing
64. If a motor is too heavy to move, you should _______.
get someone to help
15. Current flow and magnetic field strength are at their _____ value at the positive and negative peaks of the AC sine wave.
max
17. A(n) _____ control circuit is a circuit that provides control functions such as starting, stopping, jogging, direction of rotation control, speed control, and motor protection.
motor
38. The DC series motor _____. a. has the field connected in parallel with the armature b. produces the highest torque of all DC motors c. has good speed regulation d. none of these
none of above
37. Interpoles are used _____. a. to increase sparkling at the brushes b. with shunt and compound motors less than 1/2 HP c. all of these d. none of these
none of these
75. If the shunt field is connected to the same power supply as the armature, the motor is connected in the ________ configuration.
self-excited
81. When a shunt field is connected to a different power supply than the armature, it is called a(n) _______ shunt field.
separately excited
69. A DC _____ motor is one that has the field windings connected in series with the armature.
series
76. The primary advantage of a DC shunt motor is that it provides excellent _________.
speed control