Q. For matching over a range of frequencies in a transmission line it is best to use

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Q. Assertion (A): In the interaction region of magnetron an electron is subjected to three forces: force due to electric field, force due to magnetic field and centrifugal force.

Reason (R): The mechanism of generation of microwaves, in a magnetron, involves interaction of electromagnetic fields with electrons moving in static electric and magnetic fields oriented at right angles to each other.

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Q. Which of the following is wrong for a magic used to tee?

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Q. Roughly the time required for microwave cooking as compared to conventional cooking is

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Q. If the minimum range of a radar is to be doubled, the peak power has to be increased by a factor of

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Q. Which mode has the lowest cut off frequency in circular wave guides?

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Q. Assertion (A): Klystron amplifiers use one or more intermediate cavities in addition to buncher and catcher cavity.

Reason (R): When one or more intermediate cavities are used the bandwidth can be increased.

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Q. A wave Em cos (bx - ωt) is a backward wave.

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Q. In a circular waveguide TE₂₁ mode has lowest cutoff frequency

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Q. The number of TV channels which can be accommodated in a spectrum of 300 MHz is about

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Q. The noise figure of multicavity klystron amplifier is very low

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Q. Assertion (A): The velocity of electromagnetic waves on overhead lines and coaxial cables is the same.

Reason (R): Free space has an intrinsic impedance of 377 ohms.

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Q. A cavity resonator is

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Q. If antenna diameter is increased four times, the maximum range is increased by a factor of

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Q. Assertion (A): Gunn diode is a transferred electron device.

Reason (R): A Gunn oscillator uses the phenomenon of transferred electron effect.

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Q. Atomic and molecular resonance is observed in many substances

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Q. A reflex klystron oscillator is a

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Q. Consider the following applications:

1. TV tuning
2. Active filter
3. Microwave frequency multiplication

In which of above can a varactor diode be used?

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Q. Consider the following statements:

1. Dissipative attenuator has a fixed value of attenuation.
2. Reflective attenuator has a fixed value of attenuation.
3. Both dissipative and reflective attenuators are available only with fixed attenuation.
4. Both dissipative and reflective attenuators are available with either fixed or variable attenuation.

Which of the above are correct?

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Q. Impedance inversion may be obtained with

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