logo

CuriousTab

CuriousTab

Discussion

Home ‣ Electronics and Communication Engineering ‣ Communication Systems See What Others Are Saying!
  • Question

  • c(t) and m(t) are used to generate an FM signal. If the peak frequency deviation of the generated FM signal is three times the transmission bandwidth of the AM signal, then the coefficient of the term cos [2p(1008 x 103t)] in the FM signal (in terms of the Bessel Coefficients) is


  • Options
  • A. 5 J4(3)
  • B. c(t) and m(t) are used to generate an FM signal. If the peak frequency deviation of the generated FM J8(3)
  • C. c(t) and m(t) are used to generate an FM signal. If the peak frequency deviation of the generated FM J8(4)
  • D. 5 J4(6)

  • Correct Answer
  • 5 J4(6) 

    Explanation
    As, we known FM, s(t)

    c(t) and m(t) are used to generate an FM signal. If the peak frequency deviation of the generated FM

    ⟹ Frequency deviation = 3 . (AM Bandwidth) = 6 fm

    c(t) and m(t) are used to generate an FM signal. If the peak frequency deviation of the generated FM

    and ?= 6 is given in (d) only.

    ?c + n ?m = (1008 x 103)2p

    ⟹ 2p x 106 + n. 4p x 103 = (1008 x 103).2p

    ⟹ n = 4

    So, ? = 6, n = 4 hence answer is 5j4(6).

    More questions

    • 1. Tesla is a unit of

    • Options
    • A. flux
    • B. field strength
    • C. flux density
    • D. MMF
      • Discuss
    • 2. In a receiver, which of the following device has IF input but RF output?

    • Options
    • A. Demodulator
    • B. Loudspeaker
    • C. Audio amplifier
    • D. Frequency changer
      • Discuss
    • 3. In Fermi-Dirac statistics, the probability of electron occupation of an energy level equal to Fermi level is

    • Options
    • A. 0
    • B. 0.25
    • C. 0.5
    • D. 1
      • Discuss
    • 4. In a shield helix

    • Options
    • A. the spacing between adjacent turns is very large
    • B. the spacing between adjacent turns approaches zero
    • C. the spacing between adjacent turns approaches zero and wire thickness approaches zero
    • D. the spacing between adjacent turns is very large wire thickness approaches zero
      • Discuss
    • 5. Match the following:

      List I List II
      A. 200 MHz 1. SHF
      B. 20 GHz 2. UHF
      C. 500 kHz 3. VHF
      D. 500 MHz 4. MF


    • Options
    • A. A-3, B-1, C-4, D-2
    • B. A-3, B-2, C-4, D-1
    • C. A-3, B-4, C-1, D-2
    • D. A-3, B-4, C-2, D-1
      • Discuss
    • 6. A line of characteristic impedance Z0 branches into two line each with characteristic impedance Z0. The refracted voltage is

    • Options
    • A. zero
    • B. infinite
    • C. equal to incident voltage
    • D. two third of incident voltage
      • Discuss
    • 7. Iron has a body centred cubic structure.

    • Options
    • A. True
    • B. False
      • Discuss
    • 8. A surge voltage

    • Options
    • A. has very high magnitude and very long duration
    • B. has very high magnitude and very small duration
    • C. has very high magnitude and very small duration and can be positive or negative
    • D. can be only positive
      • Discuss
    • 9. The Ohm's law for conduction in metals is

    • Options
    • A. J = ?E
    • B. J =
    • C. J ? ?E
    • D. J ?
      • Discuss
    • 10. The following components are used to measure power output of a 2 kW TWT amplifier

      1. TWT
      2. Low pass/High pass filter
      3. Low power 20 dB attenuator
      4. 40 dB directional coupler with matched load
      5. Power meter.
      The correct sequence of connections of these components is:

    • Options
    • A. 1, 4, 2, 3, 5
    • B. 1, 3, 4, 2, 5
    • C. 1, 2, 4, 3, 5
    • D. 1, 4, 3, 2, 5
      • Discuss

    Comments

    There are no comments.
Enter a new Comment




Aptitude

Engineering

Programming

Reasoning

Links

Copyright ©CuriousTab. All rights reserved.