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ECE :: Electromagnetic Field Thoery

  1. What does the expression represent?

  2. A.
    Electric Energy density
    B.
    Magnetic Energy density
    C.
    Power density
    D.
    Radiation Resistance

  3. A conductor is said to be perfect if it has __________ conductivity

  4. A.
    finite
    B.
    infinite
    C.
    unity
    D.
    zero

  5. The simplest standing wave is due to the value of reflection co-efficient is

  6. A.
    -1
    B.
    zero
    C.
    unity
    D.
    infinity

  7. In terrestrial microwave links, the number of 'fades' per unit increases as

  8. A.
    both the transmission and the distance between the antennas are increased
    B.
    the transmission frequency is increased but the distance between the antennas is decreased
    C.
    the transmission frequency is decreased but the distance between the antennas is increased
    D.
    both the transmission frequency and distance between the antennas are decreased

  9. Bandwidth of an antenna is related with where Q is quality factor

  10. A.
    Q ∝ B
    B.
    Q ∝ 1/B
    C.
    Q ∝ B2
    D.
    Q ∝ 1/B2

  11. Select the correct relation

  12. A.
    ∇(AB) = A ∇ B + B ∇ A
    B.
    ∇ . (AB) = ∇ A . B + A ∇ B
    C.
    ∇ x (AB) = ∇ A x B + A ∇ B
    D.
    All of the above

  13. Diffraction of electromagnetic wave

  14. A.
    is caused by reflection from the ground
    B.
    may occur around the edge of a sharp obstacle
    C.
    arises only with spherical wavefronts
    D.
    none of these

  15. Power gain of antenna equals directive gain in VHF and UHF range if and only if efficiency of the antenna is

  16. A.
    0.25
    B.
    0.5
    C.
    0.75
    D.
    1

  17. For radiation field of an antenna at a distance r varies as


  18. For a plane good conductor, skin depth varies

  19. A.
    directly as square root of permeability
    B.
    directly as square root of frequency
    C.
    inversely as permittivity
    D.
    inversely as square root of conductivity