Information Theory and Coding MCQ

1. The secondary TDM level provides

  1. 24 channels is μ-law systems and 30 channels for A law systems
  2. 48 channels is μ-law systems and 96 channels for A law systems
  3. 96 channels in μ-law systems and 120 channels for A law systems
  4. 128 channels in μ-law systems and 200 channels for A law systems
Answer
Answer. c

2. The power gain of an antenna using paraboloid reflector is directly proportional to

  1. mouth diameter
  2. wavelength
  3. aperture ratio
  4. square of aperture ratio
Answer
Answer. d

3. In TV transmission, picture signal is amplitude modulated and sound signal is frequency modulated. This is done because

  1. it is not possible to frequency modulate the picture signal.
  2. bandwidth requirement is minimized.
  3. sound signal is more susceptible to noise than picture signal.
  4. synchronization of picture frames becomes easier.
Answer
Answer. b

4. What is the main objective of trellis coding?

  1. To narrow the bandwidth
  2. To simplify modulation
  3. To increase the data rate
  4. To reduce the error rate
Answer
Answer. b

5. If the ASCII character H is sent and the character I is received, what type of error is represented?

  1. Multiple-bit
  2. Single-bit
  3. Recoverable
  4. Burst
Answer
Answer. b

6. Which one of the following is the correct statement?

An instantaneous code is the one which can be

  1. coded rapidly
  2. coded uniquely
  3. decoded word by word without reference to succeeding code symbols
  4. decoded uniquely
Answer
Answer. c

7. Which one of the following is the correct statement?

If the channel bandwidth doubles, the S/N ratio becomes

  1. double of the former S/N ratio
  2. square root of the former S/N ratio
  3. half of the former S/N ratio
  4. none of the above
Answer
Answer. c

8. The channel capacity of a noiseless channel is equal to

  1. Rate at which information is transmitted
  2. Signalling speed
  3. Bandwidth
  4. Bandwidth-SNR product
Answer
Answer. a

9. Which one of the following statements is correct?

The equalizing pulses in television transmission are sent during

  1. vertical blanking
  2. horizontal blanking
  3. horizontal retrace
  4. picture forward trace
Answer
Answer. a

10. In which type of the switchings given below, entire capacity of a dedicated link is used?

  1. Circuit switching
  2. Data gram packet switching
  3. Virtual circuit packed switching
  4. Message switching
Answer
Answer. a

11. Consider a binary Hamming code of block length 31 and rate equal to (26/31). Its minimum distance is

  1. 5
  2. 3
  3. 31
  4. 26
Answer
Answer. b