Digital Communications MCQ

Test your knowledge with important Digital Communications MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Digital Communications MCQs at Bissoy

• Thermal noise power of a resistor depends upon
  ক

  Its resistance value

  খ

  Noise temperature

  গ

  Bandwidth

  ঘ

  Ambient temperature
• The type of noise that interferes much with high frequency transmission is
  ক

  White

  খ

  Flicker

  গ

  Transit time

  ঘ

  Shot
• The probability density function of the envelope of narrow band noise is
  ক

  Uniform

  খ

  Gaussian

  গ

  Rayleigh

  ঘ

  Rician
• The spectral density of white noise is
  ক

  Exponential

  খ

  Uniform

  গ

  Poisson

  ঘ

  Gaussian
• Vector quantization is used in
  ক

  Audio coding

  খ

  Video coding

  গ

  Speech coding

  ঘ

  All of the mentioned
• Non uniform quantizer ______ distortion.
  ক

  Increases

  খ

  Decreases

  গ

  Does not effect

  ঘ

  None of the mentioned
• The theoretical gain in zero crossing TED is greater than early late TED.
  ক

  True

  খ

  False
• In early late timing error detection method if the bit is constant, then the slope will be
  ক

  Close to zero

  খ

  Close to infinity

  গ

  Close to origin

  ঘ

  None of the mentioned
• The low pass filter at the output end of delta modulator depends on
  ক

  Step size

  খ

  Quantization noise

  গ

  Bandwidth

  ঘ

  None of the mentioned
• Which helps in maintaining the step size?
  ক

  Delta modulation

  খ

  PCM

  গ

  DPCM

  ঘ

  Adaptive delta modulation
• If step size is increased _____ occurs.
  ক

  Slope overload distortion

  খ

  Granular noise

  গ

  Slope overload distortion & Granular noise

  ঘ

  None of the mentioned
• 1 bit quantizer is a
  ক

  Hard limiter

  খ

  Two level comparator

  গ

  Hard limiter & Two level comparator

  ঘ

  None of the mentioned
• Delta modulation is
  ক

  1 bit DPCM

  খ

  2 bit DPCM

  গ

  4 bit DPCM

  ঘ

  None of the mentioned
• Prediction gain _____ for better prediction.
  ক

  Increases

  খ

  Decreases

  গ

  Remains same

  ঘ

  None of the mentioned
• The SNR value can be increased by _____ the number of levels.
  ক

  Increasing

  খ

  Decreasing

  গ

  Does not depend on

  ঘ

  None of the mentioned
• Uniform quantizer is also known as
  ক

  Low rise type

  খ

  Mid rise type

  গ

  High rise type

  ঘ

  None of the mentioned
• When the base of the logarithm is e, the unit of measure of information is
  ক

  Bits

  খ

  Bytes

  গ

  Nats

  ঘ

  None of the mentioned
• The output of an information source is
  ক

  Random

  খ

  Deterministic

  গ

  Random & Deterministic

  ঘ

  None of the mentioned
• The output of the source encoder is an analog signal.
  ক

  True

  খ

  False
• The mutual information between a pair of events is
  ক

  Positive

  খ

  Negative

  গ

  Zero

  ঘ

  All of the mentioned
• If the channel is noiseless information conveyed is ___ and if it is useless channel information conveyed is ___
  ক

  0,0

  খ

  1,1

  গ

  0,1

  ঘ

  1,0
• Which conveys more information?
  ক

  High probability event

  খ

  Low probability event

  গ

  High & Low probability event

  ঘ

  None of the mentioned
• Quantization is a _____ process.
  ক

  Few to few mapping

  খ

  Few to many mapping

  গ

  Many to few mapping

  ঘ

  Many to many mapping
• Which is a quantization process?
  ক

  Rounding

  খ

  Truncation

  গ

  Rounding & Truncation

  ঘ

  None of the mentioned
• Spread spectrum is used for
  ক

  Encrypting signal

  খ

  Hiding signal

  গ

  Encrypting & Hiding signal

  ঘ

  None of the mentioned
• Coded system are inherently capable of better transmission efficiency than the uncoded system.
  ক

  True

  খ

  False
• Lempel-Ziv algorithm is
  ক

  Variable to fixed length algorithm

  খ

  Fixed to variable length algorithm

  গ

  Fixed to fixed length algorithm

  ঘ

  Variable to variable length algorithm
• Entropy of a random variable is
  ক

  0

  খ

  1

  গ

  Infinite

  ঘ

  Cannot be determined
• The self information of random variable is
  ক

  0

  খ

  1

  গ

  Infinite

  ঘ

  Cannot be determined
• When X and Y are statistically independent, then I (x,y) is
  ক

  1

  খ

  0

  গ

  Ln 2

  ঘ

  Cannot be determined