Electronics Engineering Review Materials: Section 2 Module 7

This is the Section 2 Module 7 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.

Electronics Review Materials: Section 2 Module 7

This is the Section 2 Module 7 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 2 Module 7

Question

Answer

1. The purpose of offset nulling

To zero the output error voltage

2. A junction between two conductors that exhibits electrical characteristics under condition of changing temperature

Thermoelectric Conjunction

3. In electrical power distribution, what insulator is generally used?

Porcelain

4. Two essential parts in rotating generators

Electro/permanent Magnet and Armature Winding

5. An early version of the field effect transistor in which limited control of current carriers near the surface of a semiconductor bar or cell was obtained by an external electric field applied transversely

Fieldistors

6. Type of oscilloscope that are able to retain the display for a longer period

Storage Oscilloscope

7. Description used for generators trying to self-adjust its parameters before paralleling with online generators

Jogging

8. An op-amp has a common mode voltage gain of 10 and a differential mode voltage gain of 20,000. Calculate its CMRR

2,000

9. The change in input offset current due to temperature change

Input Offset Current Drift

10. Which of the following characteristics does not necessarily apply to an op amp

Low Power

11. In an RL circuit, the ratio of inductive reactance over resistance, XL/R increases the phase angle

Decreases

12. Acoustic feedback in a public accurate system

Serves no useful purpose

13. What bridge is used to measure both inductances, capacitances, and impedances as high as frequencies

Radio Frequency Bridge

14. An op amp should have at least how many usable terminals?

5

15. What term is applied to the use of two or more generators shared by a common load

Parallel operation

16. A 2 stage transistor amplifier whose output collector of the 1st stage provides input to the emitter of the 2nd stage. The final output is then taken from the collector of the 2nd stage.

Cascode Configuration

17. To make a basic instrumentation amplifier, it takes

3 op-amps and 7 resistors

18. High voltage is used in long distance power transmission because

The I^2R losses are low

19. The forward breakover voltage of a silicon diode is

About 0.6 V

20. The magnitude of the op amp’s input offset voltage before it gets classified as a low input offset voltage op amp should be

0.2 mV

21. Each atom in a silicon crystal has

8 valence electron / 4 of its own and 4 shared

22. A common base circuit is commonly employed as

A radio frequency power amplifier

23. Drain current in a constant current area increases when

The gate to source voltage decreases

24. Air works well as a dielectric mainly because it

Has low loss

25. When a semiconductor is reverse biased to a large enough voltage, it will conduct. The cause of this is

Avalanche Effect

26. Which one of the following is not an input/output of a 555 timer

Clock

27. The reason why a slight difference in the input bias current occurs in op amps is due to the unsymmetrical circuit component parameters. This unsymmetrical condition also produces a difference in input voltage called what?

Input Offset Voltage

28. This is a special bridge used in measuring very low resistance. The arrangement of the bridge reduces the effect of contact resistance which causes significant error in such low resistances when connected to low resistance bridges

Kelvin Double Bridge

29. What is an electronic instrument capable of showing on screen and may be on pen relative spacing of transmitter carriers, their sidebands, and harmonics

Spectrum Analyzer

30. The SCS differs from the SCR because

It has 2 gate terminals

31. Which FET has a wide and short effective channel

V-MOSFET

32. The maximum efficiency of a class AB amplifier is

Slightly less than a class B

33. In a wien-bridge oscillator, if the resistances of the positive feedback circuit are decreased the frequency

Increases

34. The frequency at which the open loop gain is equal to 1 is called

Unity gain frequency

35. Which of the following is not a characteristic of UJT

Bilateral conduction

36. The peak current that a class A amplifier can deliver to a load depends on the

Quiescent Current

37. What is the simplified version of the wheatstone bridge wherein two of the ratio arms are replaced by a 100 cm long manganin of uniform cross sections provided with a slider

Slide wire bridge

38. Substance which generates voltage when exposed to light

Photovoltaic material

39. A radio frequency oscillator usually

Has most or all of its energy at a single frequency

40. Which of the following resistor combinations provides lessened noise in an op amp circuit

Make both the feedback and input resistances as small as possible

41. The damping factor of a filter is set by

Negative feedback circuit

42. Generally, MOSFET have low power handling capability than BJTs, to increase the offset power the channel should be made

Wide and short

43. The characteristic that allows an isolation amplifier to amplify a small signal voltage in the presence of much greater noise voltages is its

CMRR

44. The main purpose of current limiting generator is

Protection of the regulator from excessive current

45. In the case of load regulation, when the load changes

The output voltage stays constant

46. A JFET circuit essentially never has

Forward bias PN junction

47. Generation of voltage in a generator can only happen when

There is a relative motion between conducting wires and magnetic lines of force

48. If a certain diode has a voltage of 3.6 volts, it operates in

Zener breakdown

49. Shifting the phase of an ac sine wave by 90 degrees

Moving it to the right or left by ¼ cycle

50. If two waves have the same frequency, the same phase, the composite wave

Has a magnitude equal to the sum of two original waves

51. In an exclusive OR gate the output is high only when

The inputs have opposite logic states

52. The stages of most isolation amplifiers are connected by

Transformers

53. Phase shift through an op-amp is caused by

The internal RC circuit

54. The frequency crystal oscillator junction is determined mainly by

Thickness of the crystal

55. Which of the following curves is the most useful

Output characteristic curve

56. The current consists mainly of holes and adjacent

Has a p-type channel

57. A circuit used for logic equalization on/off switching action of scr in series

Nodder circuit

58. Which bipolar amplifier type has some distortion in the signal wave with collector current during most but not all of the cycle

Class AB-2

59. When you apply a triangular waveform to the input of a differential, the output is

Square waveform

60. The most popular op-amp packages are the metal can 8-pin DIP and the SMT, which of these corresponds to TO-99?

Metal can

61. Which of the following does not affect the inductance of the coil?

The diameter of the wire

62. A dc generator whose excitation is produced by a winding connected to its own positive and negative terminals

Self excited shunt generator

63. Generally, in dc generators the armature winding is rotated with respect to a stationary magnetic field is produced by

permanent magnets or electromagnets

64. The purpose of the I layer of the PIN diode is to

Minimize diode capacitance

65. SALLEN key filters are

2nd order filters

66. In an AND gate the output is high

Only when all inputs are high

67. Noise in the input comparator can cause the output to

Change back and forth erratically between two states

68. Which of the following bipolar transistor circuits can provide the most amplification

Common emitter

69. The difference between a series regulator and a shunt regulator is

The type of sample circuit

70. When choosing a motor for a particular application what characteristics should you consider?

Speed, torque

71. Which statement is true regarding alternators

High speed alternators are smaller than low speed

72. Generation of voltage in a generator can only happen

When there Is relative motion between conducting wires and magnetic lines of force

73. Of the values listed, the most realistic value for an open loop gain of an op-amp is

100,000

74. An SCR differs from the 4-layer diode

It has a gate terminal

75. Push-pull amplifier that uses NPN and PNP transistors to amplify the positive and negative cycles respectively

Complementary symmetry amplifier

76. It consists of a single coil rotated in a magnetic field and produces an ac voltage

Elementary generator

77. Crossover distortion is a problem for

Class B amplifier

78. The operation of a logarithmic amplifier is based on

The logarithmic characteristic of a PN junction

79. What is the purpose of using a differential synchro than a regular synchro

Differential synchro can handle more signals and can also perform addition/substraction function

80. Once in saturation, a further increase in base current will

Not affect the collector current

81. The operation of a relaxation oscillator is based on

Charging and discharging of the capacitor

82. Synchronous type of ac motor

Uses a dc generator to supply dc excitation to the rotating field

83. What type of amplifier commonly used at the output stage of op-amps

Complementary amplifier

84. The purpose of installing thyrectors across the incoming power line to the speed control system is to

Protect drive circuits from high voltage transient surges

85. In a rectifier diode, current flows for how much of the ac cycle?

180 degrees

86. When a low pass and a high pass filter are cascaded with a band pass filter, the critical frequency of the low pass filter must be

Greater than the critical frequency of a high pass filter

87. When a voltage divider biased NPN transistor with the upper voltage divider resistor, the one connected to VCC opens,

The transistor goes into cutoff

88. A type of 4 arm capacitance bridge, in which the unkown capacitance is compared with the standard capacitance. This bridge is frequently employed to test electrolytic capacitors to which a TV polarizing voltage is applied during the measurement.

Schering bridge

89. In dc motors, when does severe arcing happens

During starting

90. In an OTA the transconductance is controlled by

Bias current

91. The 3 parts of a basic isolation amplifier are

Input, Output and power

92. The power dissipation of a class C amplifier is

Very low

93. Transient suppression minimizes the chance of

Diode failure

94. Generally, in dc motors

The armature winding is supplied with current or the armature is placed inside the set of magnetic poles

95. The multistage transistor amplifier arranged in a conventional series manner, the output voltage is forward coupled to the next amplifier

Cascaded amplifier

96. Typically an instrumentation amplifier has an external resistor used for

Setting the voltage gain

97. The T-MOSFET is a special type of

E-MOSFET

98. The wien bridge oscillator’s positive feedback circuit is

Lead/lag circuit

99. When the 2 inputs of a multiplier are connected together, the device operates a

Squaring circuit

100. In FET, the conduction path of the output is controlled by the electric field as it name implies, how does an electric field in an FET established

When the charges present at the gate choose a reverse biased junction

101. Why do you need a noise generator

When evaluating noise characteristics of amplifier

102. In the case of load regulation

When the load changes, the output voltage is phase constant

Complete List of Section 2 Modules in Electronics (Q&A)


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