This is the Section 1 Module 24 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 24
1. In an RC coupled class A amplifier
- ac loadline is steeper than ac loadline
2. The movable arm attraction-type relay is called
- armature
3. When the collector current of a transistor is zero, the transistor is
- cut-off region
4. The polarity of an induced voltage is determined by
- Lenz law
5. The equivalent series resistance of a capacitor is ideally
- zero
6. When using ohmmeter, to measure the continuity of a wire,the resistance should be for faulty (open) wire
- zero for good wire, infinite
7. Differentiator has a circuit of which the
- output is proportional to change in input
8. Integrator is a circuit of which the
- output changes original voltage with new change in voltage
9. Which transistor configuration hybrid parameter is usually specified by the manufacturer
- common emitter
10. The induced voltage in the inductor
- leads the current by 90°
11. If an OP AMP, open loop voltage gain is 100,000, the voltage gain at the open loop cut-off frequency is
70,700
12. In MOSFET, it is the foundation upon which the circuit is constructed or formed from a silicon base
- substrate
13. The magnetic field surrounding a solenoid
- like a permanent magnet
14. Which of the following material is non-magnetic
(wood, plastic, glass)
- all of the above
15. A voltage follower is
(low output impedance, high input impedance, voltage gain of 1)
- all of the above
16. What FET in which the gate electrode consist of a PN junction
- JFET
17. Transformer cannot be used as
- to step up or down of dc
18. The current that flows in a channel of a JFET when the gate-source voltage is zero
- Drain-saturation current
19. Which of the following cell is secondary cell
- lead-acid
20. FET that has a substate
(IGFET, D-MOSFET, E-MOSFET)
- all of the above
21. Efficiency of a series fed class A amplifier
25%
22. Highest gain of OP AMP
- Open loop gain
23. Highest cross sectional area
- AWG #12
24. When increasing the frequency of 500Hz to two octaves corresponds to
2 KHz
25. To minimize arcing, resistance should be added to reduce the current in
- armature winding
26. A 2200 uF, with a voltage rating of 35V is likely to be a/an
- electrolytic capacitor
27. In class B amplifier, the operating or Q point is at
- cut-off
28. Output complementary stage of OP AMP
- common collector
29. Open fuse has a resistance value approaches
- infinity
30. The output of an unfiltered half wave/full wave rectifier
- pulsating dc
31. The best way to bias a transistor amplifier
- diode bias
32. What type of meter is used to measure ac current without breaking/opening the circuit
- amp clamp probe
33. A transistor in which one or both electrodes are created by diffusion
- diffused transistor
34. A comparator does not uses
- negative feedback
35. Emitter dc current of transistor in differential amplifier
1/2 of tail current
36. What will happen to the gain of amplifier when used in high frequency
- it will decrease
37. What will happen to the leakage current when reverse current increases
- increase exponentially
38. Typical value of forward voltage of LED
2V
39. Which has higher resistance, 10 MΩ DOM or 500 kΩ/volt rating analog VOM
- analog VOM
40. To make the commercial magnet last indefinitely
it must not be subjected to (high temp., physical shock, strong demagnetizing force)
- all of the above
41. The orientation of magnetic field in vertical wire
- like that of permanent magnets
42. The base of BJT serves what purpose in FET
- gate
43. Swamping resistor in common emitter -
44. Which has unity voltage gain
- common collector
45. Disadvantage of common base
- low input impedance
46. Input stage of 741 OP AMP
- differential amplifier
47. Output stage in every OP AMP
- push pull amp
48. Open loop gain of 741 OP AMP
200,000
49. What current flows when VG=0
- source-drain current
50. What is the value of VD when ID=0
- equal to pitch-off voltage
51. Bridge where there are diodes in 2 arms and resistor in the other
- Half bridge
52. Must be consider when diode is used in high ac voltage
- average resistance
53. Phase angle of the high pass filter at passband frequency
o
54. Value of by pass capacitor must be consider for the Xc
- one tenth or less of the parallel resistance at the lowest frequency to be bypassed
55. Typical value of semiconductor resistivity
10 to 104
56. Which has negative temperature coefficient?
- carbon
57. Lowest output impedance
- common collector
58. FET with gate P-N junction
- JFET
59. A semiconductor device, a p-n junction formed by alloying a suitable material such as indium with the semiconductor
- alloy junction
60. Capacitor which explodes with wrong polarity
- aluminum electrolytic
61. When the secondary winding is shorted
- increase primary winding inductance
62. Circuit which uses capacitor
- clamper
63. In DPST, how many terminals should be solder
4
64. Internal resistance of voltmeter
- very high
65. Comparator that uses positive feedback
- Schmitt trigger
66. Input impedance of MOSFET
- higher than JFET
67. In solving thevenin’s resistance,
- short all sources
68. What happen in DC series motor if the load release
- motor overspeed
69. How many equations made with 2 principal nodes?
1
70. Which has highest leakage current?
- electrolytic
71. left hand rule for solenoid
- the left hand encircles the coil in the direction of electron flow, then the thumb points to north pole
72. equivalent circuit of triac
- 2 parallel SCR
73. diac is
- two terminal, bidirectional switch
74. output of C-size alkaline cell
- 1.5V
75. combination of many diode in a single housing
- diode array
76. drain and source can be interchange
- symmetrical JFET
77. Emitter follower is also called as
- common collector
78. In residential house wiring, the color of hot wire
- red and black
79. For best results, time constant in RC filter should be
- long
80. Inconvenient and time consuming in troubleshooting
- current measurement
81. What is slew rate?
- maximum rate at which voltage in op amp
82. Amplifier use in pulse operation
- class D
83. When the base-emitter is forward biased and base-collector is forward biased
- cut-off
84. Decrease of gain in increasing frequency
- roll- off
85. Main difference of BJT and FET
- BJT is current controlled while FET is voltage controlled
86. What FET originally has no current?
- MOSFET
87. The induced voltage in solenoid
- leads the current
88. The curve of current vs. Voltage in specific temperature
- characteristic curve
89. When multiplying complex number in polar form
- multiply the magnitude and add the angles
90. Commonly used in emergency equipment batteries
- silver zinc cells
91. Increasing size of electrode -
increases rin of the resistance
92. When discharging, hydrogen are attracted in the anode of the primary cell due to
- negative charge caused by a loss of electrons
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