| 1. | The working of a travelling wave tube is based on the interaction between ? | |
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Moving electron and the axial component of a progressive
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Moving electrons and the transverse component of a rotating magnetic field
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Moving electrons and the axial component of a steady magnetic field
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Moving electrons and the transverse component of a progressive em wave
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Report Question| 2. | In reflex Klystrons, the adjustment of volume of the anode cavity will result in change of ? | |
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output power
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output frequency of operation
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output signal to noise ratio
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output pulse-width
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| 3. | In magnetron, the electron travels in a cyclodal path because the ? | |
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anode is negative
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permanent magnet applies a strong field
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cavities are resonant
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cathode is positive
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| 4. | To prevent oscillations in the TWT which one of the following is resorted to ? | |
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Attenuator is used
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External magnetic field is provided
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Helix is used
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Bunching defocusing mechanism is used
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| 5. | The major advantage of TWT over a Klystron lies in its ? | |
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higher output
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higher frequency
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higher bandwidth
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higher gain
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| 6. | One of the following is not used as a microwave mixer or detector ? | |
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PIN diode
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Schottky-barrier diode
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Crystal diode
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Backward diode
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| 7. | In parametric amplifiers used in microwave communication systems, the pump energy mainly restricts which one of the following ? | |
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Noise level
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Operating frequency
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Gain
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Bandwidth
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| 8. | A parametric amplifier sometimes uses a circulator to ? | |
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separate the signal and idler frequencies
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improve the stability of the amplifier and gain
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permit more efficient pumping
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allow the same antenna to be used simultaneously for transmission and reception
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| 9. | A ruby maser amplifier must be cooled ? | |
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to increase BW
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to improve noise performance
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because maser amplification generates a lot of heat
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because it cannot operate at room temperature
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| 10. | A clock flange may be used to couple two waveguides ? | |
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because it is simpler than any other joint
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to increase the bandwidth of the system
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to compensate for discontinuities at the joint
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to help in the alignment of the waveguide
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