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ECE :: Microwave Communication

  1. In a magnetron the magnetic flux density is of the order of

  2. A.
    1 mWb/s
    B.
    1 Wb/m2
    C.
    106 m/s
    D.
    1012 m/s

  3. For a directional coupler the power is in the ratio of

  4. A.
    40 dB
    B.
    30 dB
    C.
    20 dB
    D.
    10 dB

  5. As regards rectangular and circular waveguides

  6. A.
    both have infinite set of TE and TM modes
    B.
    rectangular waveguide has infinite TE and TM modes but not the circular waveguide
    C.
    circular waveguide has infinite TE and TM modes but not the rectangular waveguide
    D.
    none of the above

  7. In a high frequency coaxial line and the length of line characteristic impedance is a function of

  8. A.
    properties of insulating material only
    B.
    inner and outer conductor radius only
    C.
    both (a) and (b)
    D.
    neither (a) nor (b)

  9. Assertion (A): In TE10 mode the cutoff frequency of rectangular waveguide is where a is the broad dimension and c is velocity of light.

    Reason (R): TE10 mode is the dominant mode in rectangular waveguide.

  10. A.
    Both A and R are correct and R is correct explanation of A
    B.
    Both A and R are correct but R is not correct explanation of A
    C.
    A is correct but R is wrong
    D.
    A is wrong but R is correct

  11. The usable bandwidth of ridge wave guide

  12. A.
    is lower than that of rectangular waveguide
    B.
    is higher than that of rectangular waveguide
    C.
    is almost same as that of rectangular waveguide
    D.
    is very small as compared to that of rectangular waveguide

  13. Assertion (A): In TE mode for rectangular waveguide.

    Reason (R): In TM mode for rectangular waveguide.

  14. A.
    Both A and R are correct and R is correct explanation of A
    B.
    Both A and R are correct but R is not correct explanation of A
    C.
    A is correct but R is wrong
    D.
    A is wrong but R is correct

  15. The attenuation characteristics of a loaded line is similar to that of

  16. A.
    low pass filter
    B.
    high pass filter
    C.
    band pass filter
    D.
    band stop filter

  17. A microstrip line has ∈r = 9. The normalised wavelength is about

  18. A.
    10
    B.
    2
    C.
    1
    D.
    0.4

  19. If the repeller voltage in a klystron oscillator is increased the transit time of electron

  20. A.
    will be increased
    B.
    will be decreased
    C.
    will remain the same
    D.
    either (a) or (b)