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WorksheetsPractice # 6 AC Theory
Total questions: 20
Worksheet time: 10mins
When a conductor is moved through a magnetic field, an ________ is induced in the conductor.
electromotive force (EMF)
electro-galvanic current (EMC)
electro-magnetic pulse (EMP)
electrochemical reaction (ECR)
electrostatic discharge (ESD)
Whenever a voltage or current passes through a series of changes, returns to the starting point, and then again starts the same series of changes, the series is called a __________.
cycle
period
alternation
The frequency is the number of __________________ of AC per second (1 second).
cycles
waves
periods
alternations
pulses
The time required for a sine wave to complete one full cycle is called a ________________.
alternation
cyclic time
period
The distance that a waveform travels during a period is commonly referred to as a __________.
wavelength
period length
sine length
An ________________ of voltage or current is the induced voltage or current flowing at any instant during a cycle.
intrinsic value
average value
induced value
instantaneous value
peak value
The ____________ is the largest instantaneous value.
power value
average value
induced value
peak value
minimum value
The largest single positive value occurs when the sine wave of voltage is at 90°, and the largest single negative value occurs when it is at 270°. Peak value is 1.41 times the effective value. Regarding the above statements:
Only #1 is true
Only #2 is true
Both #1 and #2 are true
Effective value is also known as the __________ value or root mean square, which refers to the mathematical process by which the value is derived.
MRS
SMS
RMS
AMS
TMS
The effective value of a sine wave is actually a measure of the __________ of the sine wave.
heating effect
resistive effect
frequency
counter EMF
amplitude
When two waves, such as current and voltage are exactly in step with each other, they are said to be in _______________.
conjunction
parallel
phase
opposition
discord
When two waveforms go through their maximum and minimum points at different times, the two waveforms are said to be _______________ with each other.
incongruent
out of phase
oblique
synchronized
aligned
The waveform that reaches its maximum or minimum value first is said to _________ the other waveform.
lag
dominate
lead
precede
follow
Most aircraft using a 24-volt DC system have special equipment that requires a certain amount of __________________ AC current.
400 hz
115 hz
50 hz
60 hz
220 hz
DC flows constantly in only one direction with a constant polarity, whereas AC current flow changes __________________ at regular intervals.
polarity and resistance
direction and polarity
voltage and current
direction and intensity
wattage and polarity
Because more and more units are being operated electrically in airplanes, the power requirements are such that a number of advantages can be realized by using AC.
1, 2, and 3 are correct statements.
1 and 2 are correct statements.
1 and 3 are correct statements.
When a conductor is moved through a magnetic field, an emf is induced in the conductor. The __________________ can be used to determine the direction of the induced emf.
generator left-hand rule
voltmeter
ammeter
ohmmeter
When a loop conductor is rotated in a magnetic field, a __________ is induced in each side of the loop.
voltage
current
electrostatic field
resistance
magnetic field
Generators used to produce an alternating current are called ____________________.
DC generators or alternators.
AC generators or commutators.
AC generators or inducers.
DC generators or inducers.
AC generators or alternators.
The value of an induced emf depends on three factors: 1. Material the wire is made from. 2. Temperature of the wire 3. Number of wires moving through the magnetic field 4. Strength of the magnetic field 5. Length of the wire 6. Speed of rotation Which of the following combinations are correct?
1, 2 and 6
3, 4 and 6
3, 5 and 6
