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ECE :: Electromagnetic Field Thoery

  1. MUF is depend upon

  2. A.

     Electron density of the ionospheric layer

    B.

     11 year sun spot cycle

    C.

     Received frequency by receiver

    D.

     Height of ionospheric layer

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  3. The radiation pattern of loop antenna is

  4. A.

     Circle

    B.

     Semicircle

    C.

     Elliptical

    D.

     Cardoid or Limacon

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  5. When a current carrying conductor is brought into magnetic field, the force that moves the conductor depends upon

  6. A.

     The value of current

    B.

     The weight of the conductor

    C.

     The direction of the conductor

    D.

     None of the above

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  7. If a and b are the dimensions of waveguide then

  8. A.

     a = 3b

    B.

     a = 2b

    C.

     a = b

    D.

     a = b/4

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  9. When a wave is incident from the more dense into a less dense medium at an angle equal to or exceeding the critical angle, the wave suffers total internal __________ .

  10. A.

     Reflection

    B.

     Refraction

    C.

     Transmission

    D.

     None of the above

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  11. Due to which of the following reasons a lightning conductor on top of a building is made into a pointed spike?

  12. A.

     Dust particles may not accumulate

    B.

     Charge per unit area becomes very high for lightening to discharge

    C.

     Rain drops may not collect

    D.

     None of the above

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  13. The useful magnetic flux obtainable from any closed surface is

  14. A.

     Unity

    B.

     Constant

    C.

     Both A and B

    D.

     None of the above

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  15. When the phase velocity of an EM wave depends on frequency in any medium the phenomenon is called

  16. A.

     Scattering

    B.

     Polarisation

    C.

     Absorption

    D.

     Dispersion

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  17. A satellite that simply reflect back the signals from one region of the earth to the other region is known as

  18. A.

     Orbiting satellite

    B.

     Geostationary satellite

    C.

     Active satellite

    D.

     Passive satellite

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  19. The main disadvantage of the two-hole directional coupler is

  20. A.

     Poor directivity

    B.

     Narrow bandwidth

    C.

     High standing wave ratio

    D.

     Low directional coupling

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