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ECE :: Communication Systems

  1. According to CCIR standards, the Vestigial Sideband (VSB)

  2. A.
    video frequencies upto 4 MHz are transmitted
    B.
    video frequencies upto 5 MHz are transmitted
    C.
    video frequencies upto 5.5 MHz are transmitted
    D.
    video frequencies upto 6 MHz are transmitted

  3. Line of sight transmission is used in

  4. A.
    radio frequencies below 1 MHz
    B.
    VHF only
    C.
    audio signals only
    D.
    VHF and UHF

  5. A typical value of insertion loss of SAW filter is

  6. A.
    15 dB
    B.
    2 dB
    C.
    40 dB
    D.
    60 dB

  7. In phase modulation, the phase deviation is

  8. A.
    proportional to the amplitude of the signal and varies with frequency
    B.
    remains constant while amplitude and frequency of signal varies
    C.
    proportional to the amplitude of the signal and independent of the frequency
    D.
    none of the above

  9. In the human eye, an image persists for a time of about

  10. A.
    1 second
    B.
    0.1 second
    C.
    0.05 second
    D.
    0.02 second

  11. The different channels in a TDM receiver are separated by

  12. A.
    integration
    B.
    differentiation
    C.
    AND gate
    D.
    OR gate

  13. In a pulsed RADAR typical value of pulse duration and pulse frequency respectively are

  14. A.
    1 μs and 50 Hz
    B.
    1 μs and 500 Hz
    C.
    4 μs and 50 Hz
    D.
    4 μs and 500 Hz

  15. In a hi-fi system the nonlinear distortion should be less than

  16. A.
    10%
    B.
    5%
    C.
    2%
    D.
    1%

  17. A pure tone at 1000 Hz has a dB level of 50 dB. If two such tones exist simultaneously the dB level is about

  18. A.
    50 dB
    B.
    53 dB
    C.
    100 dB
    D.
    200 dB

  19. The HV and other voltage supplies for a TV receiver are obtained from IHVT. The full name for this device is

  20. A.
    Internal high voltage transformer
    B.
    Integrated high voltage transformer
    C.
    Instant high voltage transformer
    D.
    Interleaved high voltage transformer