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ECE :: Electromagnetic Field Thoery

  1. For space propagation, what will be the electric field strength at receiving antenna

  2. A.
    B.
    30 WTGT
    C.
    173WT
    D.

  3. A medium is said to be isotropic when

  4. A.
    ∈ = 0
    B.
    ∈ = μ
    C.
    ∈ = σ
    D.
    ∈ is scalar constant

  5. The radiation resistance of a resonant long wire antenna of half wavelength (λ/2) is given

  6. A.
    73 Ω
    B.
    120 p
    C.
    377 Ω
    D.
    7.3 Ω

  7. A uniform wave have components

  8. A.
    in the perpendicular direction E existing while H is zero
    B.
    in the direction of propagation E existing while H is zero
    C.
    E and H are zero in direction perpendicular to direction of propagation
    D.
    E and H existing only in direction perpendicular to direction of propagation

  9. The measure of mismatch between the load and the transmission line is known as

  10. A.
    directivity
    B.
    Gain
    C.
    standing wave ratio
    D.
    reflection coefficient

  11. Ionospheric storm causes an abnormal decrease in the critical frequency.

  12. A.
    True
    B.
    False

  13. Which of the following is best excited from a waveguide?

  14. A.
    Discone
    B.
    Helical
    C.
    Biconical
    D.
    Horn

  15. In a vertical earthed antenna the base input impedance will be inductive for a height

  16. A.
    less than
    B.
    between
    C.
    between
    D.
    more than

  17. The frequencies in ultra high frequency range are propagated by means of __________ waves

  18. A.
    surface
    B.
    ground
    C.
    sky
    D.
    space

  19. Maximum effective aperture of a antenna is

  20. A.
    1.3 λ2
    B.
    0.13 λ2
    C.
    13 λ2
    D.
    3.1 λ2