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This set of Digital Communication Multiple Choice Questions & Answers (MCQs) focuses on Digital Communication Set 5
Q1 | Alternate Mark Inversion (AMI) is also known as
- pseudo ternary coding
- manchester coding
- polar nrz format
- none of the above
Q2 | The process of coding multiplexer output into electrical pulses or waveforms for transmission is called
- line coding
- amplitude modulation
- fsk
- filtering
Q3 | Eye pattern is
- is used to study isi
- may be seen on cro
- resembles the shape of human eye
- all of the above
Q4 | The criterion used for pulse shaping to avoid ISI is
- nyquist criterion
- quantization
- sample and hold
- pll
Q5 | TDM is
- analog multiplexing
- digital multiplexing
- a to d converter
- both a & b
Q6 | Random variables give relationship between _
- two random events
- probability of occurrence of two random events
- random event and a real number
- random event and its probability of occurrence
Q7 | The distribution function of random variable is
- p(x less than or equal to x)
- p(x greater than or equal to x)
- p(x less than x)
- p(x greater than x)
Q8 | The value of the probability density function of random variable is
- positive function
- negative function
- zero
- one
Q9 | Which gives the measure of randomness of the random variable?
- mean
- variance
- standard variance
Q10 | Random process is a function of
- random event and time
- random event and frequency
- random event and real number
- none of the mentioned
Q11 | A random process is called as stationary in strict sense if
- its statistics vary with shift in time origin
- its statistics does not vary with shift in time origin
- its autocorrelation vary with shift in time
- its autocorrelation does not vary with shift in time
Q12 | For a stationary process, autocorrelation function depends on
- time
- time difference
- does not depend on time
- none of the mentioned
Q13 | The autocorrelation function is maximum at
- origin
- infinity
- origin & infinity
- none of the mentioned
Q14 | Standard deviation is _
- rms value of dc
- rms value or ac
- either ac or dc
- neither dc nor ac
Q15 | The average power of white noise is
- zero
- unity
- infinity
- between zero and one
Q16 | he distribution function of -(infinity) and (infinity) is
- 0 and 1
- 1 and 0
- both 0
- both 1
Q17 | White noise has mean and _ variance.
- zero and zero
- finite and zero
- zero and finite
- one and zero
Q18 | Power spectral density function is a?
- real and even function
- non negative function
- periodic
- all of the mentioned
Q19 | Energy spectral density defines
- signal energy per unit area
- signal energy per unit bandwidth
- signal power per unit area
- signal power per unit bandwidth
Q20 | Power spectrum describes distribution of under frequency domain.
- mean
- variance
- gaussian
- none of the mentioned
Q21 | How can power spectral density of non periodic signal be calculated?
- by integrating
- by truncating
- by converting to periodic
- none of the mentioned
Q22 | What is Wiener-Khinchin theorem?
- spectral density and auto-covariance makes a fourier transform pair
- spectral density and auto-correlatioon makes a fourier transform pair
- spectral density and variance makes a fourier transform pair
- none of the mentioned
Q23 | According to Parseval’s theorem the energy spectral density curve is equal to?
- area under magnitude of the signal
- area under square of the magnitude of the signal
- area under square root of magnitude of the signal
- none of the mentioned
Q24 | Autocorrelation is a function which matches
- two same signals
- two different signal
- one signal with its delayed version
- none of the mentioned
Q25 | Autocorrelation is a function of
- time
- frequency
- time difference
- frequency difference