Home / ECE / Electromagnetic Field Thoery :: section-14

ECE :: Electromagnetic Field Thoery

  1. A loop antenna is a commonly used for

  2. A.

     Radar

    B.

     Direction finding

    C.

     Satellite communication

    D.

     All of the above

    View Answer

    Workspace

    Discuss Discuss in Forum


  3. The divergence of a vector is a scalar, while the curl of a vector is another

  4. A.

     Scalar

    B.

     Vector

    C.

     Unit vector

    D.

     None of the above

    View Answer

    Workspace

    Discuss Discuss in Forum


  5. Which antenna is a wideband antenna?

  6. A.

     Hertz antenna

    B.

     Marconi antenna

    C.

     Folded dipole

    D.

     None of the above

    View Answer

    Workspace

    Discuss Discuss in Forum


  7. The potential that appears at a point in space due to the current which caused it is called potential

  8. A.

     Accelerating

    B.

     Retardation

    C.

     Oscillating

    D.

     Lagging the current

    View Answer

    Workspace

    Discuss Discuss in Forum


  9. The minimum height of outer atmosphere is

  10. A.

     100 km

    B.

     150 km

    C.

     200 km

    D.

     400 km

    View Answer

    Workspace

    Discuss Discuss in Forum


  11. The radiation pattern of a parabola antenna is

  12. A.

     Omnidirectional

    B.

     A figure of directional

    C.

     Highly directional

    D.

     None of the above

    View Answer

    Workspace

    Discuss Discuss in Forum


  13. The virtual height of an ionospheric layer is __________ true height

  14. A.

     Equal to

    B.

     Less than

    C.

     Higher than

    D.

     No relation

    View Answer

    Workspace

    Discuss Discuss in Forum


  15. The transmitting antennas for lower frequencies (below 500 kHz) are generally

  16. A.

     Vertical grounded wire type

    B.

     Horizontal suspended wire type

    C.

     Parabolic reflector type

    D.

     Any of the above

    View Answer

    Workspace

    Discuss Discuss in Forum


  17. Which of the following will increase the antenna radiation efficiency?

  18. A.

     Use of larger section of conductor

    B.

     Providing insulation on conductor

    C.

     Top loading of antenna

    D.

     Any of the above

    View Answer

    Workspace

    Discuss Discuss in Forum


  19. According to maximum power transfer theorem, the maximum power is absorbed by one network from another network when

  20. A.

     The impedance of one of the networks is half that of the other

    B.

     The impedance of one is the complex conjugate of the other

    C.

     The impedance of one is equal to that of the other

    D.

     None of the above

    View Answer

    Workspace

    Discuss Discuss in Forum