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ECE :: Communication Systems

  1. Skip distance depends on time of day and angle of incidence.

  2. A.

     True

    B.

     False

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  3. It is found that a ship to ship communication suffers from fading. This can be avoided by using

  4. A.

     Space diversity

    B.

     Frequency diversity

    C.

     Broad band antenna

    D.

     Directional antenna

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  5. A buffer amplifier is

  6. A.

     A double-tuned amplifier

    B.

     A high gain D.C. amplifier

    C.

     A cathode follower stage

    D.

     None of the above

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  7. SSB can be generated by

  8. A.

     Filter method

    B.

     Phase cancellation method

    C.

     Good attenuation characteristics

    D.

     All of the above

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  9. What is the purpose of peak clipper circuits in radio transmitters?

  10. A.

     To prevent overmodulation

    B.

     To reduce bandwidth

    C.

     To increase bandwidth

    D.

     To regulate oscillator I/P voltage

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  11. The direction of rotation of a CD is

  12. A.

     Clockwise

    B.

     Anticlockwise

    C.

     Clockwise or anticlockwise depending on frequency of data stored

    D.

     Mostly anticlockwise but some times clockwise

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

  14. A.

     Low pass filter

    B.

     High pass filter

    C.

     Band pass filter

    D.

     Band stop filter

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  15. The characteristic impedance of a twin wire feeder used for TV signals is about

  16. A.

     1000 ohm

    B.

     500 ohm

    C.

     300 ohm

    D.

     100 ohm

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  17. In EM waves, polarization

  18. A.

     Is always vertical in an isotropic medium

    B.

     Is caused by reflection

    C.

     Is due to transverse nature of waves

    D.

     Results from longitudinal nature of waves

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  19. The frequency range of 300 kHz to 3000 kHz is known as

  20. A.

     Low frequency

    B.

     Medium frequency

    C.

     High frequency

    D.

     Very high frequency

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