1) In Alternate Mark Inversion (AMI) is
a. 0 is encoded as positive pulse and 1 is encoded as negative pulse
b. 0 is encoded as no pulse and 1 is encoded as negative pulse
c. 0 is encoded as negative pulse and 1 is encoded as positive pulse
d. 0 is encoded as no pulse and 1 is encoded as positive or negative pulse
|
Answer
Explanation
Related Ques
|
ANSWER: 0 is encoded as no pulse and 1 is encoded as positive or negative pulse
Explanation:
No explanation is available for this question!
|
|
2) Advantages of using AMI
a. Needs least power as due to opposite polarity
b. Prevents build-up of DC
c. May be used for longer distance
d. All of the above
|
3) The interference caused by the adjacent pulses in digital transmission is called
a. Inter symbol interference
b. White noise
c. Image frequency interference
d. Transit time noise
|
4) Eye pattern is
a. Is used to study ISI
b. May be seen on CRO
c. Resembles the shape of human eye
d. All of the above
|
5) The time interval over which the received signal may be sampled without error may be explained by
a. Width of eye opening of eye pattern
b. Rate of closure of eye of eye pattern
c. Height of the eye opening of eye pattern
d. All of the above
|
6) For a noise to be white Gaussian noise, the optimum filter is known as
a. Low pass filter
b. Base band filter
c. Matched filter
d. Bessel filter
|
7) Matched filters are used
a. For maximizing signal to noise ratio
b. For signal detection
c. In radar
d. All of the above
|
8) The number of bits of data transmitted per second is called
a. Data signaling rate
b. Modulation rate
c. Coding
d. None of the above
|
9) Pulse shaping is done
a. to control Inter Symbol Interference
b. by limiting the bandwidth of transmission
c. after line coding and modulation of signal
d. All of the above
|
10) The criterion used for pulse shaping to avoid ISI is
a. Nyquist criterion
b. Quantization
c. Sample and hold
d. PLL
|
11) The filter used for pulse shaping is
a. Raised - cosine filter
b. Sinc shaped filter
c. Gaussian filter
d. All of the above
|
12) Roll - off factor is defined as
a. The bandwidth occupied beyond the Nyquist Bandwidth of the filter
b. The performance of the filter or device
c. Aliasing effect
d. None of the above
|
Answer
Explanation
Related Ques
|
ANSWER: The bandwidth occupied beyond the Nyquist Bandwidth of the filter
Explanation:
No explanation is available for this question!
|
|
13) Nyquist criterion helps in
a. Transmitting the signal without ISI
b. Reduction in transmission bandwidth
c. Increase in transmission bandwidth
d. Both a and b
|
14) The Nyquist theorem is
a. Relates the conditions in time domain and frequency domain
b. Helps in quantization
c. Limits the bandwidth requirement
d. Both a and c
|
15) The difficulty in achieving the Nyquist criterion for system design is
a. There are abrupt transitions obtained at edges of the bands
b. Bandwidth criterion is not easily achieved
c. Filters are not available
d. None of the above
|
Answer
Explanation
Related Ques
|
ANSWER: There are abrupt transitions obtained at edges of the bands
Explanation:
No explanation is available for this question!
|
|
16) Equalization in digital communication
a. Reduces inter symbol interference
b. Removes distortion caused due to channel
c. Is done using linear filters
d. All of the above
|
17) Zero forced equalizers are used for
a. Reducing ISI to zero
b. Sampling
c. Quantization
d. None of the above
|
18) The transmission bandwidth of the raised cosine spectrum is given by
a. Bt = 2w(1 + α)
b. Bt = w(1 + α)
c. Bt = 2w(1 + 2α)
d. Bt = 2w(2 + α)
|
19) The preferred orthogonalization process for its numerical stability is
a. Gram- Schmidt process
b. House holder transformation
c. Optimization
d. All of the above
|
20) For two vectors to be orthonormal, the vectors are also said to be orthogonal. The reverse of the same
a. Is true
b. Is not true
c. Is not predictable
d. None of the above
|
21) Orthonormal set is a set of all vectors that are
a. Mutually orthonormal and are of unit length
b. Mutually orthonormal and of null length
c. Both a & b
d. None of the above
|
22) In On-Off keying, the carrier signal is transmitted with signal value '1' and '0' indicates
a. No carrier
b. Half the carrier amplitude
c. Amplitude of modulating signal
d. None of the above
|
23) ASK modulated signal has the bandwidth
a. Same as the bandwidth of baseband signal
b. Half the bandwidth of baseband signal
c. Double the bandwidth of baseband signal
d. None of the above
|
24) Coherent detection of binary ASK signal requires
a. Phase synchronization
b. Timing synchronization
c. Amplitude synchronization
d. Both a and b
|
25) The probability of error of DPSK is ______________ than that of BPSK.
a. Higher
b. Lower
c. Same
d. Not predictable
|
26) In Binary Phase Shift Keying system, the binary symbols 1 and 0 are represented by carrier with phase shift of
a. Π/2
b. Π
c. 2Π
d. 0
|
27) BPSK system modulates at the rate of
a. 1 bit/ symbol
b. 2 bit/ symbol
c. 4 bit/ symbol
d. None of the above
|
28) The BPSK signal has +V volts and -V volts respectively to represent
a. 1 and 0 logic levels
b. 11 and 00 logic levels
c. 10 and 01 logic levels
d. 00 and 11 logic levels
|
29) The binary waveform used to generate BPSK signal is encoded in
a. Bipolar NRZ format
b. Manchester coding
c. Differential coding
d. None of the above
|
30) The bandwidth of BFSK is ______________ than BPSK.
a. Lower
b. Same
c. Higher
d. Not predictable
|
31) In Binary FSK, mark and space respectively represent
a. 1 and 0
b. 0 and 1
c. 11 and 00
d. 00 and 11
|
32) The frequency shifts in the BFSK usually lies in the range
a. 50 to 1000 Hz
b. 100 to 2000 Hz
c. 200 to 500 Hz
d. 500 to 10 Hz
|
33) The spectrum of BFSK may be viewed as the sum of
a. Two ASK spectra
b. Two PSK spectra
c. Two FSK spectra
d. None of the above
|
34) The maximum bandwidth is occupied by
a. ASK
b. BPSK
c. FSK
d. None of the above
|
35) QPSK is a modulation scheme where each symbol consists of
a. 4 bits
b. 2 bits
c. 1 bits
d. M number of bits, depending upon the requirement
|
36) The data rate of QPSK is ___________ of BPSK.
a. Thrice
b. Four times
c. Twice
d. Same
|
37) QPSK system uses a phase shift of
a. Π
b. Π/2
c. Π/4
d. 2Π
|
38) Minimum shift keying is similar to
a. Continuous phase frequency shift keying
b. Binary phase shift keying
c. Binary frequency shift keying
d. QPSK
|
39) In MSK, the difference between the higher and lower frequency is
a. Same as the bit rate
b. Half of the bit rate
c. Twice of the bit rate
d. Four time the bit rate
|
40) The technique that may be used to reduce the side band power is
a. MSK
b. BPSK
c. Gaussian minimum shift keying
d. BFSK
|
