1. The secondary TDM level provides
- 24 channels is μ-law systems and 30 channels for A law systems
- 48 channels is μ-law systems and 96 channels for A law systems
- 96 channels in μ-law systems and 120 channels for A law systems
- 128 channels in μ-law systems and 200 channels for A law systems
2. The power gain of an antenna using paraboloid reflector is directly proportional to
- mouth diameter
- aperture ratio
- square of aperture ratio
3. In TV transmission, picture signal is amplitude modulated and sound signal is frequency modulated. This is done because
- it is not possible to frequency modulate the picture signal.
- bandwidth requirement is minimized.
- sound signal is more susceptible to noise than picture signal.
- synchronization of picture frames becomes easier.
4. What is the main objective of trellis coding?
- To narrow the bandwidth
- To simplify modulation
- To increase the data rate
- To reduce the error rate
5. If the ASCII character H is sent and the character I is received, what type of error is represented?
6. Which one of the following is the correct statement?
An instantaneous code is the one which can be
- coded rapidly
- coded uniquely
- decoded word by word without reference to succeeding code symbols
- decoded uniquely
7. Which one of the following is the correct statement?
If the channel bandwidth doubles, the S/N ratio becomes
- double of the former S/N ratio
- square root of the former S/N ratio
- half of the former S/N ratio
- none of the above
8. The channel capacity of a noiseless channel is equal to
- Rate at which information is transmitted
- Signalling speed
- Bandwidth-SNR product
9. Which one of the following statements is correct?
The equalizing pulses in television transmission are sent during
- vertical blanking
- horizontal blanking
- horizontal retrace
- picture forward trace
10. In which type of the switchings given below, entire capacity of a dedicated link is used?
- Circuit switching
- Data gram packet switching
- Virtual circuit packed switching
- Message switching
11. Consider a binary Hamming code of block length 31 and rate equal to (26/31). Its minimum distance is