Which one of the following phrasers best describes flux density?
A. The concentration of lines of magnetic force
B. The rate of change of the number of lines of magnetic force
C. The opposition to a build-up of magnetic fields
D. The force that maintains lines of force
E. None of the above
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Which is the most widely used semiconductor?
A. Copper
B. Silicon
C. Germanium
D. All of the above
E. None of the above
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The transistor has a current gain of 175. If the base current is 0.1 mA, what is the collector current?
A. 1750 mA
B. 17.5 mA
C. 175 mA
D. 1.75 mA
E. None of the above
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An intrinsic semiconductor has some holes in it at room temperature. What causes these holes?
A. Doping
B. Valence electrons
C. Free electrons
D. Thermal energy
E. None of the above
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Which one of the following statements is true?
A. Power dissipation of a pure inductor decreases with operating frequency
B. Power dissipation of a pure inductor is at a maximum for dc source voltages
C. Power dissipation of a pure inductor increases with operating frequency
D. There is no meaningful relationship between the power dissipation of a pure inductor and its operating frequency
E. None of the above
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An audio transformer has a turn ratio of 9, What is its impedance ratio?
A. 81
B. 85
C. 6
D. 9
E. None of the above
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Which one of the following statements is true?
A. The secondary voltage for a step-down power transformer is greater than the primary voltage
B. The secondary current for a step-down power transformer is greater than the primary voltage
C. Parallel RLC circuit operated below its resonant frequency
D. purely resistive circuit
E. None of the above
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How many protons does the nucleus of a silicon atom contain?
A. 4
B. 29
C. 14
D. 48
E. None of the above
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A circuit has two different voltage sources that are connected in a series-opposing form. If the sources are rated at 6 V and 9 V, what is the total source voltage?
A. 3 V
B. 16 V
C. 7.5 V
D. 8 V
E. None of the above
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The emitter diode is usually
A. Forward-biased
B. Reverse-biased
C. Nonconducting
D. Operating in the breakdwon region
E. None of the above
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1 Microfarad is the same as:
A. 1 millionth of a picofarad
B. 1000 millifarads
C. 1 million picofarads
D. 1 million farads
E. None of the above
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Which one of the following statements is true for resistance in a parallel circuit?
A. The total resistance is equal to the sum of the individual resistances in a parallel circuit.
B. The total resistance of a parallel circuit is always less than the value of the smallest resistance
C. The total resistance of a parallel circuit is equal to the total voltage
D. The total resistance in a parallel circuit is equal to the average value of the individual resistances
E. None of the above
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The direction of conventional current flow is:
A. from negative to positive
B. from positive to negative
C. from left to right
D. from neutral to positive
E. None of the above
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Doubling the operating frequency of a purely inductive circuit:
A. doubles the amount of current through the inductors
B. has no effect on the current through the inductors
C. cuts the current through the inductors one-half
D. increases the current, but by an amount that can be determined only by doing a complete analysis of the circuit
E. None of the above
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The secondary voltage for a certain power transformer is twice the voltage applied to the primary. The current flowing in the secondary winding will be:
A. One-half the primary current
B. Same as the primary current
C. Twice the primary current
D. No more than 10% less than the primary current
E. None of the above
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What is a free electron?
A. An electron that has been freed from its parent atom
B. An electron that costs nothing
C. An electron that has no electrical charge
D. An electron that has twice the amount of charge of a normal electron
E. None of the above
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To get the Norton current, you have to
A. Short the load resistor
B. Open the load resistor
C. Short the voltage source
D. Open the voltage source
E. None of the above
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The barrier potential accross each depletion layer is
A. 0
B. 0.8 V
C. 0.7 V
D. 20 V
E. None of the above
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Which one of the following properties of a magnetic circuit can be directly compared to voltage in an electrical circuit?
A. Flux density
B. Number of lines of force
C. Magnetomotive force
D. Reluctance
E. None of the above
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What kind of battery is most likely included in a cordless electric knife?
A. Zinc-carbon battery
B. Mercury-cell battery
C. Nicad battery
D. Lead-acid battery
E. None of the above
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