Home / ECE / Microwave Communication :: Section 8

ECE :: Microwave Communication

  1. In a klystron amplifier the transit time of electron passing the gap in the cavity should be

  2. A.
    less than one cycle
    B.
    less than half cycle
    C.
    less than quarter cycle
    D.
    more than quarter cycle

  3. In a cable with ∈r = 4, the wave velocity is

  4. A.
    3 x 108 m/s
    B.
    0.75 x 108 m/s
    C.
    1.5 x 108 m/s
    D.
    108 m/s

  5. In a backward wave oscillator the efficiency

  6. A.
    is much higher than in TWT
    B.
    is much lower than in TWT
    C.
    is almost the same as in TWT
    D.
    either (a) or (b)

  7. Consider the following statements

    1. Fading of signals is generally greatest near radio horizon.
    2. Fading of signals is generally greatest in shadow zone.
    3. Fading is small when a good optical path is present.
    Which of the above statements are correct?

  8. A.
    1, 2 and 3
    B.
    1 and 2 only
    C.
    1 and 3 only
    D.
    2 and 3 only

  9. The use of coaxial microwave line should be restricted to frequencies

  10. A.
    below cut off frequency of TE11 mode
    B.
    above cut off frequency of TE11 mode
    C.
    at frequencies much lower than cut off frequency of TE11 mode
    D.
    at frequencies much higher than cut off frequency of TE11 mode

  11. Generally the wall thickness of rectangular waveguide is

  12. A.
    about 1-5 mils
    B.
    about 40-100 mils
    C.
    about 0.1 to 0.5 mils
    D.
    about 500 mils

  13. If QL is loaded Q, QE is external Q and QU is unloaded Q of a microwave resonator, then

  14. A.
    B.
    C.
    D.
    QL = QE + QU