This is the Section 1 Module 8 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 8
1. What is the largest range of gm for JFET?
- 1000 micro second to 5000 micro second
2. The largest possible decimal no. that can be represented by six binary no.?
- 63
3. Which of the ff. voltage could normally represent a +1 in positive logic?
+4 V
4. Which of the ff. voltage might normally represent a +1 in negative logic?
0 V
5. A logic circuit has four inputs W, X, Y and Z. How many possible input combinations are there?
16
6. Of the ff. which material allows the lowest forward voltage drop in a diode?
Germanium
7. What is Power factor
– true power divided by apparent power
8. In TSEB, the base current must be _______.
very small.
9. An audio amplifier operates in the frequency range.
20 Hz – 20 KHz
10. For max. peak to peak output voltage, the Q point should _______.
at the center of the ac load line.
11. With Class A, the output signal should be ________.
unclipped.
12. What is an LF157A?
Bifet OP Amp.
13. When slew rate distortion of a sine wave occurs, the output ________.
appears triangular.
14. What is the transresistance of an amplifier?
ratio of its output voltage to input current.
15. What is the approximation that distorts digital signals the least?
Bessel.
16. If a filter has 2 six –second order stages and one first order stage, the order is ____.
13.
17. If n=10, the approximation with the fastest roll-off in the transition region.
Elliptic
18. A second-order all pass filter can vary the output phase from ________.
0° to 360°.
19. What is the output waveform of a 555 timer.
rectangular.
20. The state variable filter has a
low pass, high pass and bandpass filter.
21. To correct for limited GBW, a designer may use ______.
predistortion.
22. The bandwidth of the low pass filter in a PLL determines the ________.
capture range.
23. The E-Mosfet with gate connected to its drain an ________
active load.
24. At the lower or upper cutoff frequency the voltage gain is _____
0.707 amid.
25. If the inductive reactance is the same as the resistance in an RL circuit, the phase angle is ______.
45°.
26. Coherent radiation is produced by a _______.
Laser Diode.
27. A photo diode, when not used as photovoltaic cell, has _______.
reverse bias.
28. Which of the ff. amplifier classes generally needs the most driving power?
Class B
29. A tapped coil is used in a (n) :
Hartley Oscillator
30. A continuously variable signal is recovered from a signal having discrete states by:
a D/A converter
31. A typical audio recording tape thickness is
1 mil.
32. A tube with three grids is called a ________.
pentode.
33. A device consisting of a receiver and transmitter in the same box is called_______.
transceiver.
34. A platter is a part of a hard drive.
35. What is a circuit for selecting a single output from multiple inputs.
Universal Logic Module
36. When the Q points move along the load line, the voltage increases when the collector current _________.
decreases.
37. To reduce the distortion in a collector emitter amplifier, reduce the ________.
ac base voltage.
38. The ac collector current equals the ac base current times the ________.
ac current gain.
39. With active-load switching, the upper E-Mosfet is a ________.
two terminal device.
40. The tail current of a differential amplifier is ________.
two times either collector current.
41. The typical input stage of an Op Amp has ________.
differential input and single-ended output.
42. In an ac amplifier using Op Am with coupling and bypass capacitors the offset voltage is ________.
minimum.
43. The all pass filters is sometimes called ______.
delay equalizer.
44. An astable 555 timer has the ff. no. of stable states.
0
45. Thermal shutdown occurs in an IC regulator if ________.
internal temperature is too high.
46. In vector diagrams, the distance from the center of the graph represents ________.
peak amplitude.
47. As the number of turns in a coil increases, the reactance ________.
increases.
48. An unimportant factor concerning the frequency at which PN junction will work effectively is the ________.
reverse current.
49. Avalanche voltage is routinely exceeded when a PN junction acts a ________.
voltage regulator.
50. If the output wave in a circuit has the same shape as the input wave, then the circuit is ______.
linear.
51. The part of a power supply immediately preceding the regulator is the ______.
filter.
52. A resistor between the base of an NPN bipolar transistor and the positive supply voltage is used to provide ________.
proper bias.
53. If the load impedance for an oscillator is too high.
It’s not a cause to worry it can’t be too high.
54. Which type of component is generally not practical for fabrication in an IC?
Inductors
55. The control grid of a tube corresponds to the:
Gates of an FET
56. In a tube with a directly heated cathode:
the filament serves as the cathode.
57. In a tube with a cold cathode.
There is no filament.
58. A heptode has ______ grids.
five
59. In a magnetron, as the frequency is increased.
The achievable power output decreases.
60. A klystron is noted for its:
high achievable output power.
61. In a junction FET, the control electrode is usually the ______.
gate.
62. A diode can be used as a frequency multiplier because of its ________.
Nonlinearity.
63. The extent to which an oscillator maintains a constant frequency is called its ______.
Stability.
64. The effective speed of a recording or playback lead with respect to the data on a tape can be maximized by making a track.
Slanted with respect to the edges of the tape.
65. In a radio-frequency power amplifier using a vacuum tube, stability can be enhanced by using a circuit in which the ff. electrode is at RF ground potential.
Control grid
66. One way to keep inter electrode capacitance to a minimum is to:
keep wire leads short.
67. One advantage of ac (compared with dc) as a source of utility power is that
it can easily stepped up or down in a voltage.
68. The axis of the geomagnetic field is slanted with respect to the rotational axis.
69. A dc voltage-divider network is made using resistor.
70. The ability of a mechanically stressed ferromagnetic wire to recognize rapid switching of magnetization when subjected to a dc magnetic field.
Wiegand effect
71. The current gain of a transistor is the ratio of the collector current to base current.
72. What is the range of FET input impedance?
1 mega ohm to several hundred mega ohm
73. As the size of the plate in a capacitor increases, all other things being equal the value of XC decreases negatively.
74. The capacitance values in an op amplifier circuit depend on the _______.
signal frequency.
75. In a rectifier diode, current flows for approximately how much of the cycle?
180°
76. As the frequency of the ac increases, the reactance of inductor:
becomes large positively.
77. Resistivity of the wire can be specified in ________.
ohms per meter.
78. A diode that can be used as a variable capacitance:
varactor.
79. The open-loop cutoff frequency of a 741C is controlled by a compensating capacitor.
80. The unity gain frequency equals the product of closed-loop voltage gain and the closed loop cutoff frequency.
81. When Q is greater than 1, a band pass filter should be built with MFB stages.
82. A frequency synthesizer is a _____.
divider.
83. The characteristic impedance of the transmission line.
The construction of the line.
84. The drain current will always be the one-fourth of the IDSS as long as the gate to source is one-half of the pinch-off value.
85. The gain of -15 dB in a circuit, the input signal is stronger than the output.
86. In a one shot multivibrator increases, the timing capacitance increases.
87. In a common source amplifier, the output voltage is 180° out of phase with the input.
88. What law in Electronics where an induced current will be in such direction that its own magnetic field will oppose the magnetic field that produces the same?
Lenz Law
89. When Q decreases in a Colpitts oscillator, the frequency oscillations ______.
decreases.
90. Any voltage that is connected across a PN junction is called ______.
reverse voltage.
91. A 741C uses active-load resistors.
92. Frequency multiplication if possible with a semiconductor diode because the diode is ________.
nonlinear.
93. A vacuum tube would most likely be found in:
a high power radio frequency linear amplifier.
94. Sampling circuit is used in most voltage regulators.
Voltage divider network
95. In a supply design to provide high power at low voltage, the best rectification design would probably be full wave, center-tap
96. JFET might work better than a bipolar transistor in a radio receiver.
97. The phase shift through the input of an RC circuit approaches 90° as the frequency approaches 0.
98. In a reversed-biased semiconductor diode, the capacitance depends on the width of the depletion region.
99. The collector voltage of a VDB circuit is no sensitive to changes in the current gain.
100. An example of a device that commonly oscillates is Gunn diode.
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