Communication miscellaneous

Communication miscellaneous

Easy Questions
Moderate Questions
Difficult Questions

Communication

Communication miscellaneous
  1. The double-sided spectrum of xc(t) would be—








  1. View Hint View Answer Discuss in Forum

    Try yourself.

    Correct Option: B

    Try yourself.

  1. The power in normalized message signal mn (t) would be—








  1. View Hint View Answer Discuss in Forum

    Given message signal
    m(t) = 9 cos 20πt + 7 cos 60πt
    |m(t )|max = 9 + 7 = 16 at t = 0
    Therefore, the power in normalized message signal

    m(t) =
    Power in the signal m(t)
    Max. power in signal m(t)

    =
    92/2 + 72/2
    		 = 0.254
    (16)2

    Correct Option: C

    Given message signal
    m(t) = 9 cos 20πt + 7 cos 60πt
    |m(t )|max = 9 + 7 = 16 at t = 0
    Therefore, the power in normalized message signal

    m(t) =
    Power in the signal m(t)
    Max. power in signal m(t)

    =
    92/2 + 72/2
    		 = 0.254
    (16)2

  1. The disadvantage of FM over AM is that—








  1. View Hint View Answer Discuss in Forum

    Refer synopsis.

    Correct Option: B

    Refer synopsis.

  1. In NBFM, the maximum modulation frequency is 3 kHz and maximum deviation is 5 kHz. The modulation index is—








  1. View Hint View Answer Discuss in Forum

    For NBFM modulation index < 1

    Correct Option: C

    For NBFM modulation index < 1

  1. The threshold in FM depends on—








  1. View Hint View Answer Discuss in Forum

    When the carrier to noise ratio is slightly less than unity, the frequency of spike generation is small, and each spike produces individual clicking sound in the receiver. But, when the carrier to noise ratio is further decreased so that the ratio is moderately less than unity, the spikes are generated rapidly and the clicks merge into sputtering sound. This phenomenon is known as threshold effect in FM. and the level of threshold depends upon the frequency deviation and power level of frequencies radiated at the receiver.

    Correct Option: C

    When the carrier to noise ratio is slightly less than unity, the frequency of spike generation is small, and each spike produces individual clicking sound in the receiver. But, when the carrier to noise ratio is further decreased so that the ratio is moderately less than unity, the spikes are generated rapidly and the clicks merge into sputtering sound. This phenomenon is known as threshold effect in FM. and the level of threshold depends upon the frequency deviation and power level of frequencies radiated at the receiver.