### Computer Science - Electronic Principles MCQs Part 5

1. Which one of the following statements is true?

A.
Current flows in a capacitor circuit only while ions are permitted to flow through the dielectric material
B.
Current flows in a capacitor circuit only while the charge on the plates is large enough to force the dielectric to conduct electrons
C.
Current can flow in a capacitor circuit, but not through the dielectric material itself
D.
Power returned to the circuit is always greater than the power absorbed
E.
None of the above

2. What is the total resistance of a series circuit that contains four resistors having values of 220W, 470W, 1W, and 1.2W?

A.
692.2 Ohm
B.
844.5 Ohm
C.
3890 Ohm
D.
1234 Ohm
E.
None of the above

3. Holes act like:

A.
Atoms
B.
Crystals
C.
Negative charges
D.
Positive charges
E.
None of the above

4. How may valence electrons does a silicon atom have?

A.
0
B.
1
C.
2
D.
4
E.
None of the above

5. Reducing the amount of current through an inductor:

A.
reduces the value of inductance by one-half
B.
multiplies the value of inductance by four
C.
multiplies the value of inductance by two
D.
has no effect on the inductance
E.
None of the above

6. Which one of the following statements best applies to a series RLC circuit?

A. The voltage waveform for each component always has the same amplitude and phase as the applied voltage
B. The current waveform for each component always has the same amplitude and phase as the applied current
C. All of the above
D. The sum of the current is always less than the applied current
E. None of the above

7. When applying a square waveform to a capacitor, the circuit tends to:

A. peak the voltage and round off the current waveforms
B. peak the current and round off the voltage waveforms
C. round off both the voltage and current waveforms
D. peak both the voltage and current waveforms
E. None of the above

8. Which one of the following properties of a magnetic circuit can be directly compared to current in an electrical circuit?

A. Number of lines of force
B. Flux density
C. Reluctance
D. Magnetomotive force
E. None of the above

9. Who invented the first junction transistor?

A. Smith
B. Gomes
C. Fisher
D. Shockley
E. None of the above

10. When a series 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

11. Which one of the following equations most directly leads to the resistance of an ordinary household light bulb, assuming that you know the power and voltage rating?

A. R = E2/P
B. P = PR
C. P = E2/R
D. I = P/E
E. None of the above

12. The total capacitive reactance of a parallel capacitor circuit is:

A. equal to the sum of the individual capacitive-reactance values
B. equal to the sum of the individual capacitance values
C. equal to the source voltage divided by total current
D. less than the capacitance value of the smallest capacitor
E. None of the above

13. Thevenin theorem replaces a complicated circuit facing a load by an

A. Ideal voltage source and parallel resistor
B. Ideal current source and parallel resistor
C. Ideal voltage source and series resistor
D. Ideal current source and series resistor
E. None of the above

14. What kind of device is a diode?

A. Bilateral
B. Linear
C. Nonlinear
D. Unipolar
E. None of the above

15. Which one of the following statements applies to common, non-rechargeable flashlight batteries?

A. Common flashlight batteries are secondary wet-cell batteries
B. Common flashlight batteries are primary wet-cell batteries
C. Common flashlight batteries are primary dry-cell batteries
D. Common flashlight batteries are secondary dry-cell batteries
E. None of the above

16. The total inductive reactance of a parallel inductor circuit is:

A. equal to the sum of the individual inductive-reactance values
B. equal to the sum of the individual inductance values
C. equal to the source voltage divided by total current
D. less than the inductance value of the smallest inductor
E. None of the above

17. A step-down transformer has turns ration of 5:1. If the primary voltage is 120 Vrms, what is the secondary voltage?

A. 12 V
B. 18 V
C. 24 V
D. 30 V
E. None of the above

18. Norton's theorem replaces a complicated circuit facing a load by an

A. Ideal voltage source and parallel resistor
B. Ideal current source and parallel resistor
C. Ideal voltage source and series resistor
D. Ideal current source and series resistor
E. None of the above

19. Which one of the following statements regarding ac circuits is correct?

A. Current and voltage are in phase through an inductor
B. Current leads the voltage through an inductor
C. Current lags the voltage through an inductor
D. All of the above
E. None of the above

20. Doubling the operating frequency of a capacitive circuit:

A. doubles the amount of a capacitive reactance
B. has no effect on the capacitive reactance
C. cuts the capacitive reactance in half
D. multiplies the capacitive reactance by 6.28
E. None of the above

21. The net charge of a neutral copper atom is

A. 0
B. +1
C. -1
D. +4
E. None of the above

22. Which one of the following statements is true for the voltage in a parallel RL 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 inductance
C. The total voltage lags the total current by less than 90
D. The total voltages is less than the sum of the voltages across the resistance and inductance
E. None of the above

23. A low-pass filter:

A. passes lower-frequency signals and reduces higher-frequency signals
B. passes higher-frequency signals and reduces lower-frequency signals
C. has no effect on ac signals
D. reduces the level of all frequencies by a significant amount
E. None of the above

24. What is one important thing transistors do?

A. Emit light
B. Amplify weak signals
C. Regulate voltage
D. Rectify line voltage
E. None of the above

25. At room temperature an intrinsic silicon crystal acts approximately like

A. a battery
B. a conductor
C. an insulator
D. a piece of copper wire
E. None of the above

26. What is the algebraic sum of this series of values:+2, -3, -6,+4?

A. -6
B. -3
C. 0
D. +2
E. None of the above

27. When operating below its resonant frequency, a parallel RLC circuit has the characteristics of a:

A. parallel RL circuit
B. parallel RC circuit
C. parallel RLC circuit operated above its resonant frequency
D. purely resistive circuit
E. None of the above

28. What causes the depletion layer?

A. Doping
B. Recombination
C. Barrier potential
D. Ions
E. None of the above

29. Which one of the following statements most accurately reflects the nature of ac power?

A. The current in an ac circuit flows in one direction, but changes value periodically
B. The current in an ac circuit flows in one direction at a steady level
C. The current in an ac circuit changes direction periodically
D. The current in an ac circuit flows in two directions at the same time
E. None of the above

30. A step-up transformer has a turns ratio of 1:4. If the line voltage is 115 V rms, what is the peak secondary voltage?

A. 700 V
B. 707 V
C. 651 V
D. 208 V
E. None of the above

31. Which one of the following principles best describes the basic operation of a generator?

A. Like magnetic poles repel; unlike poles attract
B. Current is induced in a conductor that is moving through a magnetic field
C. Like magnetic poles attract; unlike poles repel
D. Current flowing through a conductor generates a magnetic field
E. None of the above

32. The current gain of a transistor is defined as the ratio of the collector current to the

A. base current
B. emitter current
C. supply current
D. collector current
E. None of the above

33. What is the total resistance of a parallel circuit that contains two resistors having values of 220 ohm and 470 ohm?

A. 220 ohm
B. 150 ohm
C. 445 ohm
D. 690 ohm
E. None of the above

34. The equivalent of 1 kV is:

A. 1.00 V
B. 1000 V
C. 100 mV
D. 1000 mV
E. None of the above

35. The period of a waveform is:

A. the time required to complete one full cycle
B. the number of cycles completed in one second
C. the time required for the voltage to rise from 10% to 90% of the peak amplitude
D. equal to 0.707 times the peak amplitude
E. None of the above

6. Which one of the following statements best applies to a series RLC circuit?

A. The voltage waveform for each component always has the same amplitude and phase as the applied voltage
B. The current waveform for each component always has the same amplitude and phase as the applied current
C. All of the above
D. The sum of the current is always less than the applied current
E. None of the above

7. When applying a square waveform to a capacitor, the circuit tends to:

A. peak the voltage and round off the current waveforms
B. peak the current and round off the voltage waveforms
C. round off both the voltage and current waveforms
D. peak both the voltage and current waveforms
E. None of the above

8. Which one of the following properties of a magnetic circuit can be directly compared to current in an electrical circuit?

A. Number of lines of force
B. Flux density
C. Reluctance
D. Magnetomotive force
E. None of the above

9. Who invented the first junction transistor?

A. Smith
B. Gomes
C. Fisher
D. Shockley
E. None of the above

10. When a series 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