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Free download in PDF Mobile Communication Objective Type Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
(21)
The modulation technique used for mobile communication systems during world war II was
[A]
Frequency modulation
[B]
Amplitude modulation
[C]
ASK
[D]
FSK
Answer: Frequency modulation
(22)
Paging systems could be used to
[A]
Voice message
[B]
Send numeric messages
[C]
Send alphanumeric messages
[D]
All of the above
(23)
Antenna down tilting refers to
[A]
Focusing radio energy towards ground
[B]
Decreasing the S/N ratio at the antenna input
[C]
Decreasing the strength of antenna
[D]
All of the above
Answer: Focusing radio energy towards ground
(24)
The rainbow pattern seen on a CD is an example of
[A]
Refraction
[B]
Reflection
[C]
Diffraction
[D]
None of the above
(25)
Brewster angle is the angle at which
[A]
No reflection occurs at the first medium
[B]
Reflection coefficient is zero
[C]
The wave gets refracted in the direction of source
[D]
Both a and b
(26)
Coherence time refers to
[A]
Minimum time for change in magnitude and phase of the channel
[B]
Time required for synchronization between the transmitter and the receiver
[C]
Time required to attain a call with the busy base station
[D]
None of the above
Answer: Minimum time for change in magnitude and phase of the channel
(27)
Doppler spread refers to
[A]
Large coherence time of the channel as compared to the delay constraints
[B]
Temporary failure of message transfer
[C]
Signal fading due to Doppler shift in the channel
[D]
None of the above
Answer: Signal fading due to Doppler shift in the channel
(28)
Slow frequency hopping refers to
[A]
One or more symbols transmitted in time interval between frequency hops
[B]
More than one frequency hop during each symbol
[C]
Hopping rate greater than or equal to information symbol rate
[D]
Both a and c are correct
Answer: One or more symbols transmitted in time interval between frequency hops
(29)
Working of Adaptive Equalizers include
[A]
Training
[B]
Tracking
[C]
Modulation
[D]
Both a and b
(30)
The Linear Equalizer may be implemented as
[A]
FIR filter
[B]
Lattice filter
[C]
Low pass filter
[D]
Both a and b
31
Linear equalizer is also known as
[A]
Transversal filter
[B]
Low pass filter
[C]
Lattice filter
[D]
None of the above
Answer: Transversal filter
32
PCM, DPCM, DM, ADPCM are the types of
[A]
Waveform coders
[B]
Channel allocation for transmission
[C]
Vocoders
[D]
All of the above
33
Waveform coders and Vocoders are the types of
[A]
Frequency translation methods
[B]
Modulation technique
[C]
Speech coders
[D]
Channel allocation for transmission
34
Speech Coders are categorized on the basis of
[A]
Frequency of signal
[B]
Bandwidth of the signal
[C]
Signal compression techniques
[D]
None of the above
Answer: Signal compression techniques
35
Search window of a RAKE receiver is
[A]
Frequency band of the channel
[B]
Range of the time delays
[C]
Range of noise
[D]
All of the above
Answer: Range of the time delays
36
The RAKE receiver involves the steps
[A]
Estimation of transmitted signal, demodulation, bit decision, correlator
[B]
Estimation of transmitted signal, demodulation, correlator, bit decision
[C]
Estimation of transmitted signal, correlator, demodulation, bit decision
[D]
Correlator, estimation of transmitted signal, demodulation, bit decision
Answer: Correlator, estimation of transmitted signal, demodulation, bit decision
37
In time diversity
[A]
Multiple versions of signals are transmitted at different time instants
[B]
Signal is transmitted with different polarization
[C]
The signal is transmitted using multiple channels
[D]
All of the above
Answer: Multiple versions of signals are transmitted at different time instants
38
———– introduced Frequency Modulation for mobile communication systems in 1935.
[A]
Edwin Armstrong
[B]
Albert Einstein
[C]
Galileo Galilei
[D]
David Bohm
39
DECT stands for
[A]
Digital European Cordless Telephone
[B]
Digital European Cellular Telex
[C]
Digitized Emergency Cellular Telephone
[D]
Digital European Cellular Telephone
Answer: Digital European Cordless Telephone
40
World’s first cellular system was developed by
[A]
Nippon Telephone and Telegraph (NTT)
[B]
Bellcore and Motorola
[C]
AT&T Bell Laboratories
[D]
Qualcomm
Answer: Nippon Telephone and Telegraph (NTT)
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