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ECE :: Electromagnetic Field Thoery

  1. The value of susceptibility in case of vacuum is taken as

  2. A.
    zero
    B.
    0.5
    C.
    unity
    D.
    infinity

  3. Self impedance is

  4. A.
    same for transmitting (Tt) and receiving antenna (Tr)
    B.
    Tt > Tr
    C.
    Tr > Tt
    D.
    no relation

  5. Equipotential surfaces about a point charge are in which one of the following forms?

  6. A.
    Sphere
    B.
    Planes
    C.
    Cylinders
    D.
    Cubes

  7. __________ will have the least value of relative permeability.

  8. A.
    Palladium
    B.
    Silver
    C.
    Cobalt
    D.
    Iron

  9. The relative permeability is taken as unity for which of the following?

  10. A.
    Air
    B.
    Cobalt
    C.
    Vacuum
    D.
    Bismuth

  11. The disturbance from adjacent power lines is known as

  12. A.
    cross talk
    B.
    cross fire
    C.
    inductive disturbance
    D.
    none of the above

  13. Magnesium is alloyed with conducting materials for antenna primarily with the purpose of

  14. A.
    increasing efficiency
    B.
    improving radiative power
    C.
    reducing weight
    D.
    increasing density

  15. Which of the following term applies to troposcatter propagation?

  16. A.
    SIDs
    B.
    Faraday rotation
    C.
    Atmospheric storms
    D.
    Fading

  17. Two co-axial cylindrical sheets of charge are present in free space fs = 5 c/m2 at r = 2 m and rs = -2 c/m2 at r = 4 m, The displacement flux density at r = 3 m is


  18. The effective refraction index of the ionosphere for radio wave is

  19. A.
    more than unity
    B.
    less than unity
    C.
    equal to unity
    D.
    either more or less than unity depending on the electron concentration