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  • Question
  • A reflex klystron oscillator is a


  • Options
  • A. low power device
  • B. high power device
  • C. high efficiency device
  • D. both (a) and (b)

  • Correct Answer
  • low power device 

    Explanation
    It uses a single cavity resonator for generating microwave oscillations.

    Its parts are electron gun, resonator, repeller and output coupling.

    It operates on the principle of positive feed back.

    The repeller electrode is at negative potential and sends the partially bunched electron beam back to resonator cavity.

    This positive feedback supports oscillations. Its feature are:

    1. Frequency range - 2 to 100 GHz

    2. Power output - 10 MW to about 2 W

    3. Efficiency - 10 - 20 %

    Its applications include radar receivers, local oscillator in microwave devices, oscillator for microwave measurements in laboratories etc.


    More questions

    • 1. If an amplifier with gain of - 1000 and feedback factor ? = - 0.1 had a gain change of 20% due to temperature, the change in gain of the feedback amplifier would be

    • Options
    • A. 10%
    • B. 5%
    • C. 0.2%
    • D. 0.01%
    • Discuss
    • 2. Permeability is analogous to

    • Options
    • A. resistivity
    • B. retentivity
    • C. conductivity
    • D. coercivity
    • Discuss
    • 3. In a Gunn diode oscillator drift velocity of electron is 107 cm/s and active region length is 10 x 10-4 cm. The natural frequency of oscillation is

    • Options
    • A. 1 MHz
    • B. 10 MHz
    • C. 1 GHz
    • D. 10 GHz
    • Discuss
    • 4. A cycloconverter is a group of controlled rectifiers.

    • Options
    • A. True
    • B. False
    • Discuss
    • 5. If the valence electron is separated from a copper atom, the remaining part of atom has a net charge of

    • Options
    • A. 1
    • B. - 1
    • C. 0
    • D. + 3
    • Discuss
    • 6. A single phase bridge type cycloconverter uses eight thyristors.

    • Options
    • A. True
    • B. False
    • Discuss
    • 7. ?r is determined by the atomic structure of the dielectric.

    • Options
    • A. True
    • B. False
    • Discuss
    • 8. An SBS can conduct is one direction only.

    • Options
    • A. True
    • B. False
    • Discuss
    • 9. The resistivity of intrinsic semiconductors, at room temperature, is of the order of

    • Options
    • A. 1 ?-m
    • B. 1000 ?-m
    • C. 106 ?-m
    • D. 10-3 ?-m
    • Discuss
    • 10. The orientation polarization of a polyatomic gas is inversely proportional to absolute temperature.

    • Options
    • A. True
    • B. False
    • Discuss


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