logo

CuriousTab

CuriousTab

Discussion


Home Electronics and Communication Engineering Microwave Communication See What Others Are Saying!
  • Question
  • If D is diameter of circular waveguide the cutoff wave-length for TE11 mode is equal to


  • Options
  • A. 1.706 D
  • B. 2.11 D
  • C. 0.82 D
  • D. 0.41 D

  • Correct Answer
  • 1.706 D 

    Explanation
    Some applications require dual polarization capability. Circular waveguide has this capability.

    These analysis uses cylindrical coordinates.

    In circular waveguide TE11 mode has the lowest cut off frequency and is the dominant mode.

    If D is diameter of waveguide

    ?c = 1.706 D for TE11 mode

    ?c = 1.029 D for TE21 mode

    ?c = 0.82 D for TE01 mode

    ?c = 1.306 D for TM01 mode.


    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