Networking MCQ's Set-5
81] The technique that may be used to increase average information per bit is _______
(A) Shannon-Fano algorithm
(B) ASK
(C) FSK
(D) Digital modulation techniques
ANSWER : A
82] _______ is a multilevel modulation in which four phase shift are used for representing four different symbols.
(A) ASK
(B) FSK
(C) PSK
(D) QPSK
ANSWER : D
83] The _________ is not preferred for the high speed modems since with increase in speed, the bit rate increases.
(A) ASK
(B) FSK
(C) PSK
(D) QPSK
ANSWER : B
84] _______ is used for high bit rates, where the phase of the sinusoidal carrier is changed according to the data bit to be transmitted.
(A) ASK
(B) FSK
(C) PSK
(D) QPSK
ANSWER : C
85] ASK, PSK, FSK, and QAM are examples of ________ conversion.
(A) digital-to-digital
(B) digital-to-analog
(C) analog-to-analog
(D) analog-to-digital
ANSWER : B
86] In QAM, both ________ of a carrier frequency are varied.
(A) frequency and amplitude
(B) phase and frequency
(C) amplitude and phase
(D) none of the above
ANSWER : C
87] In ________, the amplitude of the carrier signal is varied to create signal elements. Both frequency and phase remain constant.
(A) ASK
(B) FSK
(C) PSK
(D) QAM
ANSWER : A
88] In ________, the phase of the carrier is varied to represent two or more different signal elements. Both peak amplitude and frequency remain constant
(A) ASK
(B) FSK
(C) PSK
(D) QAM
ANSWER : C
89] Quadrature amplitude modulation (QAM) is a combination of ___________.
(A) ASK and FSK
(B) ASK and PSK
(C) PSK and FSK
(D) none of the above
ANSWER : B
90] ________ uses two carriers, one in-phase and the other quadrature.
(A) ASK
(B) FSK
(C) PSK
(D) QAM
ANSWER : D
91] Analog-to-analog conversion is needed if the available bandwidth is _______.
(A) low-pass
(B) band-pass
(C) either (a) or (b)
(D) neither (a) and (b)
ANSWER : B
92] _______ encoding has a transition at the middle of each bit.
(A) RZ
(B) Manchester
(C) Differential Manchester
(D) all of the above
ANSWER : D
93] In a _____ scheme, all the signal levels are on one side of the time axis, either above or below.
(A) polar
(B) bipolar
(C) unipolar
(D) none of the above
ANSWER : C
94] How many carrier frequencies are used in BFSK?
(A) 2
(B) 1
(C) 0
(D) None of these
ANSWER : A
95] The constellation diagram of 16-QAM has ______ dots.
(A) 4
(B) 16
(C) 8
(D) None of these
ANSWER : B
96] The Federal Communications Commission (FCC) allows ______kHz for each AM station.
(A) 5
(B) 10
(C) 20
(D) None of these
ANSWER : B
97] The maximum synchronizing capability in coding techniques is present in
(A) Manchester format
(B) Polar NRZ
(C) Polar RZ
(D) Polar quaternary NRZ
ANSWER : A
98] Polar coding is a technique in which
(A) 1 is transmitted by a positive pulse and 0 is transmitted by negative pulse
(B) 1 is transmitted by a positive pulse and 0 is transmitted by zero volts
(C) Both (A) & (B)
(D) None of the above
ANSWER : A
99] In polar RZ format for coding, symbol ‘0’ is represented by
(A) Zero voltage
(B) Negative voltage0
(C) Pulse is transmitted for half the duration
(D) Both b and c are correct
ANSWER : D
100] In a uni-polar RZ format,
(A) The waveform has zero value for symbol ‘0’
(B) The waveform has A volts for symbol ‘1’
(C) The waveform has positive and negative values for ‘1’ and ‘0’ symbol respectively
(D) Both a and b are correct
ANSWER : D
