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EEE :: Modulation and Demodulation

  1. In a superhetrodyne receiver, the difference frequency is chosen as the IF rather than the sum frequency because ___________

  2. A.

     The difference frequency is closer to oscillator frequency

    B.

     Lower frequencies are easier to amplify

    C.

     Only the difference frequency can be modulated

    D.

     None of the above


  3. Modulation is done in ___________

  4. A.

     Transmitter

    B.

     Radio receiver

    C.

     Between transmitter and radio receiver

    D.

     None of the above


  5. Demodulation is done in ___________

  6. A.

     Receiving antenna

    B.

     Transmitter

    C.

     Radio receiver

    D.

     Transmitting antenna


  7. In the above question, what is the power in sidebands?

  8. A.

     8 kW

    B.

     6 kW

    C.

     06 kW

    D.

     9 kW


  9. Superhertodyne principle refers to

  10. A.

     Using a large number of amplifier stages

    B.

     Using a push-pull circuit

    C.

     Obtaining lower fixed intermediate frequency

    D.

     None of the above


  11. At 100% modulation, the power in each sideband is ___________ of that of carrier

  12. A.

     50%

    B.

     40%

    C.

     60%

    D.

     25%


  13. In a transmitter ___________ oscillator is used

  14. A.

     Hartley

    B.

     RC phase-shift

    C.

     Wien-bridge

    D.

     Crystal


  15. If level of modulation is increased ___________ power is increased

  16. A.

     Carrier

    B.

     Sideband

    C.

     Carrier as well as sideband

    D.

     None of the above


  17. Overmodulation (amplitude) occurs when signal amplitude is ___________ carrier amplitude

  18. A.

     Equal to

    B.

     Greater than

    C.

     Less than

    D.

     None of the above


  19. If modulation is 100% then signal amplitude is ___________ carrier amplitude

  20. A.

     Equal to

    B.

     Greater than

    C.

     Less than

    D.

     None of the above