This is the Section 1 Module 5 of the compiled Electronics Review Materials taken from different sources including but not limited to Electronics books, past Board Exams Questions, Journals and the Internet. This particular reviewer in Electronics Engineering has random Questions and Answers in random topics. Make sure to familiarize each questions to increase the chance of passing the ECE Board Exam.
Electronics Engineering Reviewers: Section 1 Module 5
1. A broken fuse is indicated by
- An LED
2. Kelvin electrostatic voltmeter employs what kind of damping?
- Fluid friction
3. The Thevenin resistance is equal in value to the ____
- Internal resistance of a Norton circuit
4. The net charge of a neutral atom
- 0
5. If you wanted to produce a p-type semiconductor, which of these would you use?
- Acceptor atoms
6. What is true about the breakdown voltage in a zener diode?
- It is approximately constant
7. Which of these is the best description of a zener diode?
- It is a constant-voltage device
8. Most of the electrons in the base of an NPN transistor do not recombine because they
- Have a long lifetime
9. If the emitter resistance doubles with TSEB, the collector current will
- Drop in half
10. The majority carriers in the emitter of a PNP transistors are
- Holes
11. For class B operation, the collector current flows
- Half the cycle
12. If the input voltage to an emitter follower is too large, the output voltage will be
- Clipped
13. The voltage that turns on an EMOS device is
- Threshold voltage
14. Most PFETs are
- Used in high-current applications
15. An RC snubber protects an SCR against
- False triggering
16. The stray wiring capacitance has an effect on the
- Upper cutoff frequency
17. In op-amps, the difference between two base currents is..
- Input offset current
18. When the two input terminals of a diff amp are grounded..
- An output error voltage usually exist
19. What usually controls the open-loop cutoff frequency of an op-amp?
- Compensating capacitance
20. The cutoff frequency of an op-amp equals the unity gain frequency divided by…
- Closed-loop voltage gain
21. The 741C has unity-gain frequency of…
- 1 Mhz
22. With an ICVS amplifier, the circuit approximates an ideal
- Current-to-voltage converter
23. A VCVS amplifier has no output voltage. A possible trouble is…
- Shorted load resistor
24. The closed-loop input impedance in a VCVS amplifier is
- Usually larger than the open-loop input impedance
25. In the classic three op-amp instrumentation amplifier, the differential gain is usually produced by the…
- First stage
26. When a JFET is used in an AGC circuit, it acts like a…
- Voltage-controlled resistance
27. A bandstop filter is sometimes called a…
- Notch filter
28. The elliptical approximation has a…
- Rippled stopband
29. To get a Butterworth response with an 8th-order filter, the stages need to have…
- Staggered Q’s
30. The output of a relaxation oscillator is a…
- Square wave
31. A comparator with a trip-point of zero is sometimes called a…
- Zero-crossing detector
32. A wien-bridge is sometimes called a…
- Notch filter
33. The most widely used oscillator is the…
- Colpiits
34. The 78XX series of voltage regulators produces an output voltage that is…
- Positive
35. A series regulator is more efficient than a shunt regulator because…
- It switches the pass transistor on and off
- The pass transistor replaces the series resistor
36. The efficiency of a linear regulator is high when the…
- Headroom voltage is low
37. In a buck regulator, the output voltage is filtered with a
- Choke-input filter
38. A VCVS amplifier approximates an ideal
- Voltage amplifier
39. An advantage of a toroid coil over solenoid core is:
- The toroid confines magnetic flux
40. In a transformer, a center tap would probably found in:
- Balanced winding
41. Selenium works especially well in:
- Photocells
42. The purpose of doping is to:
- Give a semiconductor material certain properties
43. Which of the following would make the best filter for a power supply?
- A capacitor in parallel and a choke in series
44. If you needed exceptionally good ripple filtering for a power supply, the best approach would be to:
- Use two capacitor/choke sections one after the other
45. To service a power supply with which you are not completely familiar, you should…
- Leave it alone and have a professional work on it
46. The greatest possible amplification is obtained in…
- A CE circuit.
47. The enhancement-mode MOSFET can be recognized in schematic diagrams by:
- A broken vertical line inside the circle
48. A graphic equalizer is a form of…
- Tone control
49. An IMPATT diode…
- Is used as a microwave oscillator
50. VBE of an ideal transistor
- 0.7 V
51. Instruments that are used as reference for calibration
- Standard instruments
52. Unit of Susceptance and Elastance
- Siemens
53. Kirchoff’s 2nd Law
- Voltage Law (Vsupply = ∑ Vdrop)
54. When an electron is taken from an atom, the net charge of that atom would be
+1
55. The purpose of adding Schockley diode to TTL
- To improve switching speeds
56. Bandwidth decreases as…
- Q increases
57. Has negative resistance region
- Tunnel diode
58. Protection for meter instruments
- Ayrton shunt
59. Eddy current…
- Increases core loss
60. Why complex numbers are used to represent impedance?
- It can describe what is really happening in the circuit
61. Threshold voltage of Power regulator ICS is nearest to
- 2V
62. You are required to get the impedance of a parallel RLC circuit, which of the following is the best approach you can do?
- Get the elastance and susceptance, obtain the reciprocal to get the impedance in the form R + jX
63. The ripple factor of a full wave rectifier
- 48 %
64. In BJT, the voltage across the emitter is approximately equal to the difference of ______ and 0.7V.
- VBASE
65. A device which you will use when the temperature of operation is higher than what mercury thermometer can handle
- Pyrometer
66. Which of the following has no insertion error?
- Clamp meter
67. A circuit has no output voltage. A possible cause would be…
- Shorted load resistance
68. Has higher thermal stability than solenoid core
- Air core
69. In a common emitter circuit, one parameter which you should obtain first is…
- Base current
70. Highest possible voltage supply for EMOS
- 24V
71. Reciprocal of Impedance
- Admittance
72. The reason why you are aligning the pointer to infinity for an ohmmeter is…
- To compensate the aging if the battery
73. When there is no signal to be connected in the input, the input-ends are…
- Either pull-up or pull-down depending on the function of the circuit
74. In opamp, input offset voltage is sometimes represented as…
- battery
75. The decrease in threshold voltage for every 1°C increase of temperature
- 2mV
76. Preferred core for a value of 1.5 H
- Pot core
77. For a BJT to operate in active region, VBE and VCE should be ______ and ________ respectively
- Forward – reversed
78. When FET met its pinch-off voltage, supply voltage…
- Became very negative
79. Without current limiting, a shorted load would probably
- It destroys diodes and transistors
80. Supply voltage of a PMOS can be up to…
- 24 V
81. Drain current in FET is the…
- Total dc current
82. Eddy current…
- Increases I2R losses
83. Oscilloscope…
- Displays analog voltage of individual signals
84. Output current of 714C op amp
- 25 mA
85. Element/device that controls the amount of current or voltage
- Control element
86. The phase of a signal can be measures starting from…
- Zero-positive going
87. Susceptance and conductance add to form
- Admittance
88. Flip flop connection which the input of the first flipflop is connected to the inpu signal while the input of the other flipflop is connected to the output of the first flipflop
- Master/Slave flipflop
89. The period of a pulse is measured…
- Between two similar points of a signal
90. If you change dielectric of the capaitor, capacitance will…
- not enough data to answer
91. R=300ohms, XC=30ohms…
- Current leads voltage by several degrees
92. One way to protect power supplies from high voltages is by the used of
- Reversed-diode as limiters
93. To reduce oscillations in an amplifier which will undergo on different impedances, you may use
- Optoisolator
94. If you want to produce p type semiconductor, what will you use?
- Acceptor atoms
95. The electrons in the emitter on an npn must have enough potential to overcome the barrier across
- emitter-base junction
96. If the compensating capacitor is several inches from the input of the IC, stray capacitance may be produced. This can be prevented by…
- Connecting bypass capacitor at the input of the IC
97. The majority carriers of the emitter of a PNP transistor are
- holes
98. What do you call the difference in input offset voltage due to temperature
- Input offset voltage drift
99. Short circuit output current of 741C op amp
- 25 mA
100. What will happen to the circuit if you add several capacitors in parallel?
- Ripple decreases
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