The direction of electron current flow is:
A. from right to left
B. from positive to negative
C. from negative to positive
D. from neutral to positive
E. None of the above
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A device that converts mechanical pressure to electrical energy is called a:
A. piezoelectric device
B. solar cell
C. photodiode
D. nicad cell
E. None of the above
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Which one of the following statements is true for the voltage in a parallel RC circuit?
A. The voltage always has the same amplitude and phase for every part of the circuit
B. The total voltage is equal to the sum of the voltages across the resistance and capacitance
C. The total voltage leads the total current by less than 90 degree
D. The total voltage is less than the sum of the voltages across the resistance and capacitance
E. None of the above
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The Thevenin resistance is equal in value to the
A. Load resistance
B. Half the load resistance
C. Internal resistance of a Morton circuit
D. Open-load resistance
E. None of the above
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Most AC power is obtained from:
A. generators
B. batteries
C. oscillators
D. lightning
E. None of the above
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The value of a capacitor can be made larger by:
A. increasing the area of the plates
B. decreasing the area of the plates
C. increasing the frequency of the applied voltage
D. increasing the voltage applied to the plates
E. None of the above
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The value of a capacitor can be made larger by:
A. moving the plates further apart
B. moving the plates closer together
C. increasing the voltage applied to the plates
D. decreasing the voltage applied to the plates
E. None of the above
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The primary impedance of a transformer is 60 ohm and the secondary impedance is 120 ohm. What is the impedance ratio?
A. 0.25
B. 180
C. 0.5
D. 4
E. None of the above
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Suppose a voltage source has an ideal voltage of 12V and an internal resistance of 0.5W. For what values of load resistance will the voltage source appear stiff?
A. 5 Ohm
B. 50 Ohm or more
C. 100 Ohm
D. 6 Ohm
E. None of the above
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Electron current is flowing through a conductor in a direction you might describe as straight into this page. What is the direction of the resulting magnetic field?
A. Clockwise
B. Counterclockwise
C. Out of this page
D. Into this page
E. None of the above
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Which one of the following principles best describes the basic operation of an electromagnet?
A. Current is induced in a conductor that is moving through a magnetic field
B. Like magnetic poles repel, while unlike poles attract
C. Current flowing through a conductor generates a magnetic field
D. Like magnetic poles attract, while unlike poles repel
E. None of the above
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The transistor has a collector current of 2 mA. If the current gain is 135, what is the base current?
A. 14.8 µA
B. 10.3 µA
C. 7.8 µA
D. 7.75 µA
E. None of the above
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Current and voltage are said to be in phase when:
A. their waveforms are both ac or both dc
B. they have the same amplitude and frequency
C. their waveforms cross through zero and reach positive and negative peaks at the same time
D. All of the above
E. None of the above
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Silicon atoms combine into an orderly pattern called a
A. Crystal
B. Covalent bond
C. Semiconductor
D. Valence orbit
E. None of the above
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The rotating coil of wire in an electric motor is called the:
A. armature
B. brush
C. commutator
D. loop
E. None of the above
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The north pole of a magnet is the one:
A. that has its molecules arranged in a random pattern
B. that would be attracted to the earth's north magnetic pole
C. that would be repelled by the south pole of another magnet
D. that would be attracted to the earth's south magnetic pole
E. None of the above
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A resistor has a rated value of 100 ohm and a tolerance of 10%. What is its minimum and maximum allowable resistance value?
A. 90 Ohm - 101 ohm
B. 90 Ohm - 110 ohm
C. 98 Ohm - 100.1 ohm
D. 99 Ohm - 102 ohm
E. None of the above
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When a parallel RLC circuit is operating at its resonant frequency:
A. capacitive reactance is greater than the inductive reactance
B. inductive reactance is greater than the capacitive reactance
C. inductive reactance is equal to the capacitive reactance
D. the difference between inductive and capacitive reactance is equal to the resistance
E. None of the above
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For normal operation of the transistor, the collector diode has to be
A. Forward-biased
B. Reverse-biased
C. Nonconducting
D. Operating in the breakdown region
E. None of the above
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In a step-down transformer, which is larger?
A. Primary voltage
B. Secondary voltage
C. Neither
D. Impossible to say
E. None of the above
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