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ECE :: Electromagnetic Field Thoery

  1. The discone antenna is

  2. A.
    a useful direction finding antenna
    B.
    used as a radar receiving antenna
    C.
    useful as a UHF receiving antenna
    D.
    circular polarized like other circularly antenna

  3. If a EM wave propagating in z direction then

  4. A.
    component of EM wave will exist in z direction
    B.
    component of EM wave will not exist in z direction
    C.
    component of EM wave will exist in y direction
    D.
    component of EM wave will exist in x direction

  5. The thin parallel wires are carrying current along the same direction. The force experienced by one due to the other is

  6. A.
    parallel to the lines
    B.
    perpendicular to the lines and attractive
    C.
    perpendicular to the lines and repulsive
    D.
    zero

  7. Mutual impedance is not depend upon

  8. A.
    magnitude of induced current
    B.
    tuning condition
    C.
    self impedance
    D.
    phase relationship between induced and original currents

  9. The dimension of flux density is

  10. A.
    MT-1Q-1
    B.
    MT-2
    C.
    MT1Q1
    D.
    MT-1Q-2

  11. An alternating current or voltage is that which

  12. A.
    changes in magnitude only
    B.
    changes in direction only
    C.
    both (a) and (b)
    D.
    has a random movement of electrons

  13. When the magnetic vector is parallel to the boundary surface and electric vector is parallel to the place of incidence, the polarization is

  14. A.
    zero
    B.
    vertical
    C.
    perpendicular
    D.
    horizontal

  15. The total electrical energy emitted overall space from an electron of charge e and radius r is

  16. A.
    e0r2
    B.
    e20r
    C.
    e2/4pε0r2
    D.
    e2/8pε0r

  17. In broadside array

  18. A.
    the principle direction radiation is perpendicular to the array axis and also to the plane containing the array elements
    B.
    the principle direction radiation is parallel to the array axis and also to the plane containing the array elements
    C.
    the principle direction radiation is parallel to the array axis and perpendicular to the plane containing the array elements
    D.
    the principle direction radiation is perpendicular to the array axis and parallel to the plane containing the array elements

  19. Which of following antenna does not depend upon the frequency?

  20. A.
    Log-periodic
    B.
    Parabolic
    C.
    Conical
    D.
    All of the above