Principles Of Electrical Communication MCQs

Multiple Choice Questions 35 Pages

Mahatma Gandhi University

BSc Computer Science

MPC

Contributed by

Manpreet Prasad Chaudhuri

PRINCIPLES OF ELECTRICAL COMMUNICATION
For Off Campus BSc Computer Science Programme
UNIT 1

1. In electric and electronic communications, all the audio, video and data information like
sounds, pictures, typed information, etc., is transformed into electrical signals and then
transmitted through_______________.
A. Wires
B. Fibers
C. Via wireless
D. All of the above
2. What are the basic properties of any electrical signal?
A. Frequency
B. Amplitude
C. Phase
D. All of the above
3. Which forms of signals are used to communicate, display, store and manipulate information?
A. Analog signals
B. Digital signals
C. Both (a) and (b)
D. Amplitude
4. Name the basic components of any communication system?
A. Transmitter
B. transmission medium
C. Receiver
D. All of the above
5. In which type, data is transmitted only in one direction; for example, TV or radio
transmission?
A. Channel links
B. Full duplex
C. Half duplex
D. Simplex
6. In full duplex, how many wires are needed to transmit data in different directions?
A. Three
B. Two
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C. Four
D. Five
7. In sound generating machines the small voltages are produced by___________.
A. Microphones
B. Radio
C. Telephone
D. Fax
8. While designing which device one has to ensure that the signals are transmitted accurately so
that information is not corrupted when it is sent?
A. Radio
B. Telephones
C. Data packages
D. Fax machines
9. What are designed to set the channel accurately, adjust the volume, etc., by sending signals
from the remote to the TV?
A. TV remote
B. Mobile phone
C. Fax machine
D. None of the above
10. Nowadays, signal processing is often done after converting different signals into digital
signals—the process referred to as___________.
A. Digital signal processing or DSP
B. Electrical signals
C. Both (a) and (b)
D. None of the above
11. What does digital signal offer with respect to the distortion, attenuation and noise than analog
system?
A. Accuracy of the signal
B. Quality of the signal
C. Both (a) and (b)
D. Time of the transmission
12. In digital signal, each pulse represents on or off a binary digit, which is popularly known as
__________.
A. Digital signal processing
B. Electrical signals
C. bit
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D. None of the above
13. The simplest representation for a signal is to represent the signal as a function of time
like___________.
A. Analog signals
B. Digital signals
C. Sinusoidal signals
D. None of the above
14. Binary is two level signals signifying on or off and is represented as_______.
A. 0 or 1
B. 1 or 0
C. 1
D. -1 or 0
15. Bit rate is the number of bits transmitted_________.
A. Per second
B. Per minute
C. Per hour
D. None of the above
16. The PCM system employs how many steps to accomplish its job?
A. Two
B. Three
C. Four
D. One
17. Filtering is applied to filter the frequencies below__________.
A. 400 Hz and above 4400 Hz
B. 100 Hz and above 400 Hz
C. 200 Hz and above 3000 Hz
D. 300 Hz and above 3400 Hz
18. The frequencies below _________ is filtered because they tend to involve mainly electrical
noise and therefore causing enormous attenuation and distortion in the transmitted signal because
of a number of electrical appliances present in the vicinity.
A. 3400 Hz
B. 200 Hz
C. 300 Hz
D. None of the above
19. The actual bandwidth of the filtered signal is 3100 Hz (3400–300) which is often known
as_________.
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A. 4 kHz
B. 2 kHz
C. 1 kHz
D. 5 kHz
20. According to the Nyquist theorem, the analog signal is sampled at the rate of the highest
frequency of the signal. In this case the higher frequency is 4 KHz, therefore, the analog signal is
sampled ____ times per second.
A. 5000
B. 8000
C. 2000
D. 1000
21. Which step involves quantization of the amplitude of the incoming samples to one of 255
amplitudes on a quantizing scale?
A. Quantizing
B. Sampling
C. Filtering
D. None of the above
22. The quantized samples are encoded into a digital bit stream consisting of series of electrical
pulses in which a digital encoder recognizes how many different voltage levels of the quantized
samples?
B. 245
C. 105
D. 255
23. The digital signal is converted back to its analog form in how many steps?
A. Four
B. Three
C. Two
D. None of the above
24. How many ways are there to communicate, display, store or manipulate information?
A. One
B. Four
C. Three
D. Two
25. Which process is used to smooth out the stream of 8,000 pulses per second into an analog
waveform that closely resembles the waveform that was input into the A/D converter at the
originating end?
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A. Digital-to-analog conversion
B. Filtering
C. Sampling
D. Encoding
26. What deals with data or information transmission?
A. Data communications
B. Networks
C. Both (a) and (b)
D. Signals
27. Analog is best explained by the transmission of signal, such as _________over an electrified
copper wire.
A. Sound
B. Human speech
C. Both (a) and (b)
D. Colour
28. Information which is analog in its native form (audio and image) can vary continuously in
terms of___________.
A. Intensity (volume or brightness)
B. Frequency (tone or color)
C. Both (a) and (b)
D. Human speech
29. In its native form, human speech is an oscillatory disturbance in the air, which varies in terms
of its_________.
A. Volume or power (amplitude)
B. Pitch or tone (frequency)
C. Both (a) and (b)
D. Analog signals
30. The electromagnetic sinusoidal (waveform) or sine wave can be varied in amplitude at a
fixed frequency, using__________.
A. Amplitude Modulation (AM)
B. Frequency Modulation (FM)
C. Cable television (CATV) video channel
D. Band-limiting filters
31. Computers are ________in nature.
A. Electromagnetic
B. Analog
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C. Digital
D. None of the above
32. _________ refers to a path between two or more points along which an electrical current
flows.
A. Networks
B. Channels
C. Circuits
D. None of the above
33. The circuit may be a physical path comprising of ______wires.
A. One or more
B. Two or more
C. Less than two
D. One
34. We can define a periodic function through the following mathematical expression, where t
can be any number and T is a positive constant.
A. f (t) = f (T)
B. f (t) = f (T + t)
C. f (t) = f (t)
D. None of the above
35. A signal is formally defined as a function of one or more independent variables, which
conveys information on the nature of a physical phenomenon. The variables may be______.
A. Amplitude
B. Frequency
C. Phase
D. All of the above
36. The impulse signal is also called_________.
A. Delta signal
B. Generalized function
C. Both (a) and (b)
D. Continuous-time signal
37. Who discovered that it is possible to decompose a composite signal into its constituent parts,
a set of sine functions, each with a frequency, amplitude, and phase?
A. A programmer named Fourier
B. A mathematician named Frank
C. A mathematician named Fourier
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D. None of the above
38. What is the term for the amount of time taken by a signal for one repetition of the signal?
A. Period (T)
B. Phase (φ)
C. Frequency
D. None of the above
39.______ is the range of frequencies contained in a signal.
A. Effective bandwidth
B. Absolute bandwidth
C. Spectrum
D. Fundamental frequency
40._________ means the facts information statistics or the like derived by calculation or
experimentation.
.
A. Asynchronous communication
B. Baud Code or International Telegraph Alphabet #2 (ITA#2)
C. Datum
D. None of the above
41. A cable television (CATV) video channel is approximately of________.
A. 16 MHz
B. 6 MHz
C. 4 MHz
D. 8 MHz
42. The equipment required to convert digital data to analog format and transmitting the digital
bit streams over an analog network can be__________.
A. Expensive
B. Susceptible to failure
C. Can create errors in the information
D. All of the above
43. A continuous-time signal p(t) is said to be a __________ if it exists for a definite interval of
time.
A. Unit Ramp Function (DT)
B. Pulse signal
C. Ramp signal
D. None of the above
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44. A continuous-time sinusoidal signal, in its most general form, may be written as________.
A. x(t) = A sin(ω0t +φ
B. x(t) = A cos(ω t +φ)
C. Both (a) and (b)
D. x(n) = A cos(ω n +φ )

45.__________ is one in which all frequency components of a signal are integer multiples of one
frequency.
A. Frequency domain
B. Frequency
C. Absolute bandwidth
D. Fundamental frequency
46. A bandwidth is directly proportional to the capacity of a signal to carry information, and
therefore, a _________always remains thirsty for bandwidth.
A. Data communication engineer
B. Communication engineer
C. Computer engineer
D. None of the above
47. A composite signal is defined as a signal made of many_________:
A. Complex sine waves
B. Single sine waves
C. Simple sine waves
D. None of the above
48. Higher frequency signals offer greater________.
A. Bandwidth
B. Sine waves
C. Transmission
D. None of the above
49. In data communication, there are data communication jargons to contend with such
as_______.
A. LAN, WAN, TCP/IP, ISDN
B. Baud rate
C. Modems and routers
D. All of the above
50. Emile Baudot, a Frenchman, prepared a code in which year?
A. 1857
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B. 1875
C. 1775
D. 1757
51. In which country is the Baud code sometimes known as the Murray Code?
A. Belgium
B. India
C. USA
D. UK
52. In which year, Alexander Graham Bell’s telephone experiments started the history
continuous-time sinusoidal signal
A. 1876
B. 1856
C. 1800
D. 1866
53. A telephone is a user-end-instrument to send and receive voice frequency signals. Voice
frequency for use in telephone falls between___________.
A. 300 Hz and 3000 Hz band
B. 200 Hz and 2000 Hz band
C. 300 Hz and 5000 Hz band
D. None of the above
54. A telephone connection, therefore, is an analog connection from an end user to the nearest
telephone company office, which is popularly known as___________.
A. Central Office (CO) or exchange
B. Public Switched Telephone Network (PSTN)
C. Public Telephone Network (PTN)
D. None of the above
55. Extended Binary-Coded Decimal Interchange Code was developed in which year?
A. 1780s
B. 1960s
C. 1860s
D. 1970
56. ASCII is a 7-bit code, which results in an upper limit of _______characters?
A. 130
B. 128
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C. 150
D. 129
57. The first communication satellite was launched during_________.
A. 1970s
B. 1980s
C. 1960s
D. None of the above
58. In the year 1948, Claude Shannon worked for the Bell Telephone Company in which
country?
A. United Kingdom
B. United States of America
C. Europe
D. Australia
59. Data circuit terminating equipment is also known as_________.
A. Communications software
B. Data Terminal Equipment
C. Data Communication Equipment
D. None of the above
60. Data is transmitted in one direction at a time, for example, a_________.
A. Fire alarms
B. Door bells
C. Walkie-talkie
D. None of the above

UNIT 2

61. In information technology, a _____ is an element, such as optical fibre, through which a
message is communicated?
A. Medium
B. Computer
C. Media
D. None of the above
62. Media is the plural form of__________.
A. Communication
B. Middle
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Principles Of Electrical Communication MCQs

Principles Of Electrical Communication MCQs

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