Home / ECE / Communication Systems :: Section 1

ECE :: Communication Systems

  1. A cordless telephone using separate frequencies for transmission in base and portable units is known as

  2. A.
    duplex arrangement
    B.
    half duplex arrangement
    C.
    either (a) or (b)
    D.
    neither (a) nor (b)

    View Answer

    Workspace

    Discuss Discuss in Forum


  3. For attenuation of high frequencies we should use

  4. A.
    shunt capacitance
    B.
    series capacitance
    C.
    inductance
    D.
    resistance

    View Answer

    Workspace

    Discuss Discuss in Forum


  5. A modem is classified as low speed if data rate handled is

  6. A.
    upto 100 bps
    B.
    upto 250 bps
    C.
    upto 400 bps
    D.
    upto 600 bps

    View Answer

    Workspace

    Discuss Discuss in Forum


  7. VSB modulation is preferred in TV because

  8. A.
    it reduces the bandwidth requirement to half
    B.
    it avoids phase distortion at low frequencies
    C.
    it results in better reception
    D.
    none of the above

    View Answer

    Workspace

    Discuss Discuss in Forum


  9. A woofer should be fed from the input through a

  10. A.
    low pass filter
    B.
    high pass filter
    C.
    band pass filter
    D.
    band stop filter

    View Answer

    Workspace

    Discuss Discuss in Forum


  11. The colour subcarrier and sidebands produced by its modulation with the chrominance signals are accommodated in the standard channel width by the process of

  12. A.
    frequency adjustment
    B.
    frequency interleaving
    C.
    frequency changing
    D.
    frequency amalgamation

    View Answer

    Workspace

    Discuss Discuss in Forum


  13. In FM signal with a modulation index mf is passed through a frequency tripler. The wave in the output of the tripler will have a modulation index of

  14. A.
    mf
    B.
    3mf
    C.
    mf/3
    D.
    mf/9

    View Answer

    Workspace

    Discuss Discuss in Forum


  15. In colour TV receiver, varactor diode is used for

  16. A.
    detection
    B.
    rectification
    C.
    tuning
    D.
    both (a) and (b)

    View Answer

    Workspace

    Discuss Discuss in Forum


  17. The number of noise sources in a BJT are

  18. A.
    3
    B.
    2
    C.
    1
    D.
    4

    View Answer

    Workspace

    Discuss Discuss in Forum


  19. Energy content of atmospheric noise

  20. A.
    does not depend on frequency
    B.
    decreases as frequency is increased
    C.
    increases as frequency is increased
    D.
    either (a) or (c) depending on the temperature

    View Answer

    Workspace

    Discuss Discuss in Forum