Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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The rotational speed of a motor is measured in units of ________________.
a. | resolutions per minute | d. | All of these | b. | turns per second | e. | None of these | c. | revolutions per
minute |
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2.
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Instruments that are designed to measure motor speed are called
___________.
a. | speedometers | c. | RPM meters | b. | tachometers | d. | dynamometers |
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3.
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Which of the following is an advantage of using a photo tachometer?
a. | No direct contact with the motor shaft. | d. | All of these | b. | Less
expensive. | e. | None of
these | c. | Quicker to use. |
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4.
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When a motor is ____________, the speed will decrease drastically from its rated
speed.
a. | oversized | c. | reversed | b. | unplugged | d. | overloaded |
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5.
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The amount of torque created is determined by the amount of force applied and
___________.
a. | the distance from the pivot point where force is applied | d. | None of
these | b. | the diameter of the object the force is applied to | e. | All of these | c. | the speed at which
the force is applied |
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6.
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The S.I. units of torque are _______________.
a. | nanometers | d. | All of these | b. | kilometers | e. | None of these | c. | Neutron-meters |
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7.
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Torque is developed in an electric motor because of ________________.
a. | gravity | c. | interaction of different magnetic fields | b. | inertia | d. | kinetic energy |
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8.
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The amount of torque that a motor must generate at its shaft to drive the device
it is driving is call the _________________.
a. | opposing force | d. | All of these | b. | load | e. | None of these | c. | regulator |
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9.
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The relationship between the torque input and output of a gear drive depends on
___________.
a. | the speed of the motor | d. | All of these | b. | the size of the motor | e. | None of these | c. | the direction of
rotation |
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10.
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In a belt drive system, the torque output delivered by the system depends on
____________.
a. | the diameter of the drive pulley | d. | All of these | b. | the diameter of the
driven pulley | e. | None of
these | c. | the torque output of the motor |
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11.
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If a gear attached to a load has more teeth than a gear attached to the motor,
the speed of the load will be ______________ the speed of the motor.
a. | more than | c. | the same as | b. | less than | d. | None of these |
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12.
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Which of the following is a method used to determine motor torque?
a. | Prony brake | c. | Dynamometer | b. | Current measurements | d. | All of these |
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13.
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A quick test to determine if a motor’s torque demand is too high is to
measure the motor ________________.
a. | current | c. | resistance | b. | voltage | d. | inductance |
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Matching
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SEGMENT 1
a. | tachometer | e. | photo | b. | can | f. | overload | c. | revolutions per
minute (RPM) | g. | cannot | d. | internal gear |
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14.
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The rotational speed of a motor is measured in __________.
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15.
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The device that is most often used to measure motor speed is the ______.
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16.
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A ______ tachometer determines motor shaft speed by counting the number of
times reflective tape on the motor shaft passes through its light.
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17.
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One of the applications of measuring motor speed is to check for possible
_________ condition of an AC motor.
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18.
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A hand-held mechanical tachometer has a(n) ___________ system that converts the
rotating motion of a shaft into a reading on a dial.
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19.
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A tachometer __________ be used to check the performance of speed controls.
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SEGMENT 2
a. | load | e. | newton-meters | b. | magnetic fields | f. | exceeds | c. | pulley | g. | pivot-point | d. | torque | h. | opposite |
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20.
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_________ is a measure of the turning effort caused by a force acting on a part
that rotates.
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21.
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The S.I. units for torque are _________.
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22.
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Torque is increased by either applying the force further from the ________ or
by increasing the force applied.
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23.
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The _______ on an electric motor is the amount of torque that the motor must
generate at its shaft to overcome the resistance caused by the device that is driven.
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24.
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To turn a load, the electric motor must generate a torque that _____ the torque
requirements of the load.
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25.
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On a drive belt system, the torque that is delivered to the load depends on the
_______ ratio.
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26.
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The effect that the gear or pulley ratio has on speed is exactly __________ to
the effect on torque.
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27.
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Torque is developed in an electric motor because of the interaction of
different __________.
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SEGMENT 3
a. | overloaded | d. | generator | b. | service life | e. | current | c. | prony
brake | f. | dynamometer |
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28.
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Three methods used to determine motor torque are __________, current
measurements, and dynamometer.
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29.
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An application for measuring motor torque is to determine if the motor is
____________.
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30.
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A dynamometer is basically a DC _____________.
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31.
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As motor torque increases on an electric motor, ___________ also
increases.
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32.
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A __________ is directly coupled to a motor shaft.
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33.
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Operating a motor in an overload condition results in a shortened _________.
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