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ECE :: Electromagnetic Field Thoery

  1. A TEM wave incident obliquely on a dielectric boundary with εr1 = 2 and εr2 = 1, the angle of incidence for total reflection is

  2. A.
    30°
    B.
    60°
    C.
    45°
    D.
    90°

  3. The total field produced by an antenna array system at a distance from it is

  4. A.
    sum of the field produced by the individual antennas of the array system
    B.
    directional gain of antenna
    C.
    linear antenna gain
    D.
    vector sum of the field produced by the individual antennas of the array system

  5. A perfect conductor is a perfect absorber of electromagnetic waves.

  6. A.
    True
    B.
    False

  7. In a lead acid cell the density of the acid gives an indication of

  8. A.
    the level of the acid
    B.
    the eventual damages caused to the plates
    C.
    the charge of the battery
    D.
    the e.m.f. of the battery

  9. A (0.75 - j50) ohm load is connected to a coaxial transmission line of Z0 = 75 ohms at a frequency of 10 GHz Which of the following will be the best method of matching?

  10. A.
    Connecting an inductance at the end
    B.
    Connecting a short circuited stub at the load
    C.
    Connecting a capacitance at some distance from the load
    D.
    Connecting a short circuited stub at some specified distance from the load

  11. Ground wave propagation is useful for

  12. A.
    microwave
    B.
    medium wave
    C.
    short wave
    D.
    long distance

  13. Radiowaves are electromagnetic waves having frequency range

  14. A.
    0.001 to 50 H
    B.
    0.001 to 50 kHz
    C.
    0.002 to 50 MHz
    D.
    0.001 to 1016 Hz

  15. When a line of any odd multiple of a quarter wavelength is short-circuited it represents

  16. A.
    unit impedance
    B.
    infinite impedance
    C.
    zero impedance
    D.
    none of the above

  17. An antenna is considered to be in free space where its height above the ground is

  18. A.
    λ
    B.
    C.
    less than 3λ
    D.
    more than 5λ

  19. In waveguide Degenerate modes are

  20. A.
    two mode having same cut off frequency
    B.
    two mode having same power
    C.
    two mode having same phase velocity
    D.
    it is a hypothetical mode