Completion
Complete each
statement.
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1.
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The sinusoidal waveform or _______ wave is the fundamental type of alternating
current (ac) and alternating voltage.
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2.
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Sinusoids are produced by two types of sources: rotating electrical machines (ac
generators) or electronic oscillator circuits, which are used in instruments commonly known as
electronic ________ generators.
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3.
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The combined positive and negative alterations make up one ______ of a sine
wave.
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4.
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The time required for a given sine wave to complete one full cycle is called the
_________.
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5.
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The period of a sine wave can be measured from a zero crossing to the next
______________ zero crossing.
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6.
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___________ is the number of cycles that a sine wave completes in one
second.
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7.
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The more cycles completed in one second, the higher the ____________.
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8.
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Frequency is measured in units of _________.
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9.
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One hertz is equivalent to one cycle per ________.
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10.
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The peak value of a sine wave is the value of voltage (or current) at the
positive or the negative maximum (peaks) with respect to ____________.
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11.
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Since positive and negative peak values are equal in __________, a sine wave is
characterized by a single peak value.
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12.
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The maximum or peak value of a sine wave is also called its __________.
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13.
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The term _______ stands for root mean square.
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14.
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The rms value of sinusoidal voltage is actually a measure of the ________ effect
of the sine wave.
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15.
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The value of the ac voltage can be adjusted so that the resistor gives off the
same amount of _______ as it does when connected to the dc source.
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16.
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The rms value of a sinusoidal voltage is equal to the dc voltage that produces
the same amount of heat in a resistance as does the ___________ voltage.
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17.
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The ________ value of a sine wave is defined over a half-cycle rather than a
full cycle.
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18.
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A degree is an angualar measurement corresponding to 1/360 of a _________ or a
complete revolution.
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19.
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A ________ (rad) is the angle formed when the distance along the circumference
of a circle is equal to the radius of the circle.
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20.
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The ________ of a sine wave is an angular measurement that specifies the
position of that sine wave relative to a reference.
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21.
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When the sine wave is shifted left or right with respect to this reference,
there is a ______ shift.
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22.
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Electrical utilities generate ac with ________ phases that are separated by 120
degrees.
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23.
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The three phases can be split up by the utility company to supply three ________
single phase systems.
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24.
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Single-phase power is distributed to ___________ and small commercial
buildings.
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25.
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The sine wave amplitude, A, is the maximum value of the ____________ or current
on the vertical axis.
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26.
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A phasor quantity is one that have both magnitude and ________ (phase
angle).
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27.
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If a sinusoidal voltage is applied across a resistor, there is a ______________
current.
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28.
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Power in resistive ac circuits is determined the same as for dc circuits except
that you must use _______ values of current and voltage.
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29.
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An ___________ is an ac generator that converts energy of motion into electrical
energy.
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30.
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Both the dc generator and the alternator, which generates ac voltage, are based
on the principle of electromagnetic induction that produces a voltage when there is relative motion
between a magnetic field and a ____________.
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31.
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In an alternator, each revolution of the loop produces one cycle of a _______
wave.
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32.
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If it takes 1/60 of a second to make a revolution, the period of the sine wave
is 1/60 of a second and the frequency is ______Hz.
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33.
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Another way of achieving a higher frequency is to use more __________
poles.
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34.
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A wound rotor enables control over the strength of the _________ field by
controlling the rotor current and hence the output voltage.
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35.
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Alternators are used in nearly all modern ___________, trucks, tractors, and
other vehicles.
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36.
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An induction motor is so named because a magnetic field ________ current in the
rotor, creating a magnetic field that interacts with the stator field.
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37.
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In a synchronous motor, the rotor moves in sync as the rotating field of the
________.
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38.
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As the stator field moves, the rotor moves in sync with it in a synchronous
motor but lags behind in an ___________ motor.
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39.
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The rate the stator field moves is called the ____________ speed of the
motor.
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40.
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_______ is defined as the difference between the synchronous speed of the stator
and the rotor speed.
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41.
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The induction motor has a rotor that is electrically isolated from a supply, ans
the synchronous motor uses a ___________ to follow the rotating stator field.
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42.
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The ________ is basically a graph-displaying device that traces a graph of a
measured electrical signal on its screen.
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Matching
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a. | Sine Wave | e. | Phase | b. | Waveform | f. | Pulse | c. | Cycle | g. | Frequency | d. | Peak Value | h. | Harmonics |
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43.
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The frequencies contained in a composite waveform, which are integer multiples
of the pulse repetition frequency.
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44.
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The voltage or current value of a waveform at its maximum positive or negative
points.
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45.
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A type of waveform that consists of two equal and opposite steps in voltage or
current separated by a time interval.
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46.
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A type of waveform that follows a cyclic sinusoidal pattern
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47.
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The pattern of variations of a voltage or current showing how the quantity
changes with time.
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48.
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One repetition of a periodic waveform
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49.
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A measure of the rate of change of a periodic function; the number of cycles
completed in 1s and has the units of hertz.
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50.
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The relative angualr displacement of a time-varying waveform in terms of its
occurance with respect to a reference.
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