Electronics Engineering Review Materials: Section 1 Module 15 | ECE Board Exam

This is the Section 1 Module 15 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 15

1. You are told that a certain air conditioner is rated at 500BTU. What is this KwH?

0.147

2. The freq.of common household ac in the US is

60hz

3. Suppose you double the V in the single DC circuit, and reduce the resistance in half. The current will become

four times as great

4. A resistor is specified as having a value of 68, but is measured with an ohmmeter as 63 ohms. The value is off by :

7.4%

5. The force between a magnet and a piece of ferromagnetic metal that has not been magnetized.

is never repulsive

6. A relay is connected into a circuit. So that a device gets a signal only when the relay coil carriers current. The relay is

normally open

7. Every chemical element has its own unique type of particle called is

atom

8. If the inductance is small

the energy is released slowly

9. Air works well as a dielectric mainly because it

has low losses

10. A phase difference of 180 degree in the circular model represent

½ cycle

11. Shifting the hase of an ac sine wave by 90 degree is the same thing as

moving it to the right or left by ¼ cycle

12. A phase difference of 540 degree would more often be spoken of as

phase opposition

13. A sine wave are in phase opposition. Wave x has a peak amplitude of 4v and wave y has a peak amplitude of 8v. the resultant has a peak amplitude of

4v in phase with wave y

14. If x lead wave y by 45 degree of wave y then,

wave y is 1/8 cycle behind wave x

15. If wave x lags wave y by 1/3 cycle. Then

wave y is 120 degree earlier than x

16. If the resistance R and the XL both vary from zeroth unlimited values but are always in the ratio 3:1 the point in the RL plane for all resulting impedance will fall away.

a ray of unlimited length.

17. A vector is a quantity that has

magnitude and direction

18. In an RL circuit. A as the ratio of Xl to Fc. Xl/Fc decreases, the angle

decrease

19. In an purely reactive circuit. The phase angle is

90 degree.

20. If R increases in an RC circuit. But Xc is always 0 then the vector I the RC plane circuit.

always point straight towards the right

21. If the Fc increases in an RC circuit. But the C and freq. are non – 0 and constant, then the vector in the RC plane will

get longer and rotate counterclockwise

22. The impedance vector 0 – j22 represents.

a pure capacitance

23. If the conductor of a coaxial cable is made to have smaller diameter, all other things being equal, what will happen to the Zo of the transmission line?

it will increase

24. When R = 0 in a series RLC circuit. But the net X is not 0 then impedance vector

none of the above

25. Which of the FF. is the most important consideration in a transmission line

minimizing the loss

26. A problem that standing waves can cause is

all of the above

27. Which of the FF. does not increase the loss in a transmission line?

reducing the power output of the source

28. The C bet. The primary and the secondary winding of a transformer can be minimized by

placing the winding on opposite sides of a toroidal core

29. A transformer has a secondary – primary turns ratio of 0.167 the transformer is

step down unit

30. Which of the FF. is false concerning air core versus ferromagnetic cores?

air concentrates the magnetic line of flux

31. If there is reactance at the output of an impedance transformer

there will be an impedance mismatch, no matter what the turns ratio of the transformer

32. Mutual inductance causes the net value of a set of coils to

vary depending on the extent and phase of mutual coupling

33. If R denotes resistance Z denotes absolute value impedance the R/Z is

power factor

34. The rate of change (derivative) of a sine wave is itself a wave that

leads the original wave by 90 degree of phase

35. True power is equal to

vector difference of VA and reactive power

36. The reactance of a section of transmission line depends on all of the FF. except

current in the line

37. The term “ semiconductor” arises from

variable conductive properties of some materials

38. The most common semiconductor among the FF. substance is

silicon

39. The purpose of doping is to

give a semiconductor material certain properties

40. The current through a transistor depends on

more than one of the above

41. In a common base circuit. The output is taken from the

collector

42. When a JFET is pinched off

dIG/dEG is 0 with no signal

43. Which of the FF. circuit. generally has the greatest gain

common source

44. If a circuit. Has a voltage gain. Amplification factor of 20, then the voltage gain is

26 dB

45. A diode a capacitor can be used to detect

AM

46. The S+N / N ratio is measure of

sensitivity

47. A receiver that responds to a desired signal, but not to one very nearby in freq. has good

adjacent channel rejection

48. Because of small size of Ics compared with equivalent circuits made from discrete components

higher switching speeds are attainable

49. In the united states, a license is required for

transmitting on amateur radio freq.

50. 1Mb is the same amount of data as

1024 kb

51. The web would probably work fastest for a user in New York at

2:00am local time on a Tuesday

52. The character string [email protected] might represent

an email address

53. A millivolt is

10^-3V

54. A circuit has a complex impedance of 9 + j12. The absolute impedance is

15 ohms

55. An advantage of LEO communication satellite system over a geostationary communications satellite is te fact that.

large, high gain antennas are not required

56. An audio oscillator that uses two amplifiers is cascade, with + feedback from the output of the 2nd stage to the input of the 1st stage is known is as

multivibrator

57. Electron-hole pairs are produced by

thermal energy

58. Ratio of speed between the main memory and vertical memory

10

59. Wirewound resistor is normally used in:

high power DC

60. What is the cutoff frequency has a high pass filter with constant k?

¼ pi square root of LC

61. What is the atomic no. of germanium?

32

62. What is the atomic no. of silicon?

14

63. The valence shell of silicon atom has a number designation of:

3

64. Produces pulsating or alternating current or voltage:

Oscillator

65. What circuit configuration has the highest input resistance?

Common-Collector

66. What process is done in women with no sign of beast cancer?

Screening mammogram

67. Permanent magnet moving coil is also called as:

D’ Arsonval

68. What is Friction welding?

Solid state welding

69. Maximum rate of change of output voltage of an op-amp:

Slew rate

70. What instrument has deflection whose magnitude of the electrical quantity is measured directly?

Secondary instrument

71. Carbon zinc cell to produce 24 volts in series:

16 cells

72. The algebraic sum of the current entering and leaving a node or junction in an electrical circuits zero:

Kirchoff’s law

73. Fixed Negative supply regulator used in industry:

79XX

74. Controls open-loop cutoff frequency:

Compensating capacitance

75. Valence electrons are:

In the most distant orbit from the nucleus

76. The nucleus of an atom contains:

Proton and neutron

77. Silicon crystal has:

8 valence electron, four shared, four owned

78. Atom is consists of:

1 nucleus, 1 or more proton and electron, and neutron

79. It is a four-arm bridge and used in measuring resistance:

Wheatstone or resistance bridge

80. High frequency resistance welding uses:

450 khz

81. What is a photoconductive effect?

– An increased conductivity in an illuminated semiconductor junction

82. Why is chloresteric liquid crystal colored?

Because of the slight twist between layers

83. Every known element has a:

unique type of atom

84. Computer literacy consists of the following components: I. awareness II. Knowledge III. interaction

I, II and III

85. Microprocessor-based robotic system works in conjunction with solid state memory devices. What are these devices?

1 to 4

86. If stepper motor has 200 steps per revolution, what is the angle movement of rotor per step?

1.8

87. In an inverting amplifier, close-loop gain is calculated by:

The feedback resistance divided by the input resistance

88. A step by step instruction that run a computer:

software

89. The portion of restricted envelope where the robot usually used in performing its programmed motions:

operating envelope

90. The impedance vector 5 + j0 is:

A pure resistance

91. Each impedance in R + jXL:

all of the choices

92. In semiconductor crystal, atoms are held together by:

all of the choices

93. The current-carrying part of FET, analogous to garden hose:

channel

94. The difference between insulator and semiconductor:

all of the choices

95. In vector diagrams, the length of the vector is the:

Peak amplitude

96. The energy band where free electron exists:

Conduction band

97. A positive ion is formed when:

a valence electron breaks away from the atom

98. Image reception in super heterodyne receiver is enhanced by:

Front-end selectivity

99. DC voltmeter with low sensitivity gives accurate measurement for:

Low resistance circuit

100. Two waves are 180 degrees out of phase. This is a difference of:

½ cycle

Section 1 Modules: Reviewers in Electronic Engineering