# Data Communication and networking Mcqs for the preparation of Competitive exams

71. In PCM, an analog-to- _______ conversion occurs.
a. Analog
b. Digital
c. QAM
d. Differential

b. Digital

72. If the maximum value of a PCM signal is 31 and the minimum value is -31, how many bits were used for coding?
a. 4
b. 5
c. 6
d. 7

c. 6

73. RZ encoding involves _______ signal levels.
a. Five
b. Four
c. Three
d. Two

c. Three

74. Which quantization level results in a more faithful reproduction of the signal?
a. 2
b. 8
c. 16
d. 32

d. 32

75. n _______ transmission, bits are transmitted over a single wire, one at a time.
a. Asynchronous serial
b. Synchronous serial
c. Parallel
d. (a) and (b)

d. (a) and (b)

76. In _______ transmission, a start bit and a stop bit frame a character byte.
a. Synchronous serial
b. Asynchronous serial
c. Parallel
d. (a) and (b)

b. Asynchronous serial

77. If a symbol is composed of 3 bits, there are _______ data levels.
a. 2
b. 4
c. 8
d. 16

c. 8

78. The Nyquist theorem specifies the minimum sampling rate to be_______.
a. Twice the bandwidth of a signal
b. Twice the highest frequency of a signal
c. Equal to the lowest frequency of a signal
d. Equal to the highest frequency of a signal

b. Twice the highest frequency of a signal

79. Pulse rate is always _______ the bit rate.
a. Less than
b. Less than or equal to
c. Greater than
d. Greater than or equal to

b. Less than or equal to

80. AM and FM are examples of ________ modulation.
a. Analog-to-analog
b. Analog-to-digital
c. Digital-to-digital
d. Digital-to-analog