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ECE :: Microwave Communication

  1. Standard mismatches are used to calibrate SWR and impedance measuring equipments.

  2. A.
    True
    B.
    False

  3. As compared to LED, LASER has

    1. higher emission efficiency
    2. no tuning arrangement
    3. narrow spectral width
    4. provision for confinement
    Of these statements

  4. A.
    1, 2, 3 are correct
    B.
    1, 2, 4 are correct
    C.
    1 and 3 are correct
    D.
    1, 3, 4 are correct

  5. Microwaves are used for

  6. A.
    telephony
    B.
    radio broadcast
    C.
    TV systems
    D.
    all of the above

  7. In a shield helix

  8. 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

  9. Consider the following statements about hybrid ring

    1. Ports 1 and 2 are decoupled.
    2. Port 3 and 4 are coupled.
    3. A signal entering either port 1 or 2 splits equally between ports 3 and 4.
    4. A signal entering either port 3 or 4 splits equally between ports 1 and 2.
    Which of the above are correct?

  10. A.
    1, 2, 3 and 4
    B.
    1, 3 and 4
    C.
    1 and 2
    D.
    2, 3 and 4

  11. TM01 mode in circular waveguide is analogous to

  12. A.
    TM10 mode in square waveguide
    B.
    TM11 mode in square waveguide
    C.
    TM20 mode in square waveguide
    D.
    TM02 mode in square waveguide

  13. In microwave system, waveguide twists

  14. A.
    change the plane of polarization of a propagating wave
    B.
    change the direction of a propagating wave
    C.
    change the mode of a propagating wave
    D.
    both (b) and (c)

  15. Guide wavelength (λg), cutoff wavelength (λc) and free space wavelength (λ0) of a waveguide are related as


  16. A 'rat race' is a

  17. A.
    hybrid junction for microwaves
    B.
    a microwave oscillator
    C.
    a microwave amplifier
    D.
    a microwave antenna

  18. A directional coupler is used

  19. A.
    to transmit microwave signals
    B.
    to generate microwave signals
    C.
    to measure amplitude and phase of a travelling wave
    D.
    both (a) and (b)