Q. The frequency of oscillations obtained from a reflex klystron depends mainly on

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Q. The main advantage of TWT over klystron is

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Q. In a TWT the phase velocity of the axial component of the field on the slow wave structure is kept

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Q. Assertion (A): Two equal and opposite travelling waves result in a standing wave.

Reason (R): The ratio of maximum to minimum value of a standing wave is called SWR.

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Q. When a wave reaches an open circuit

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Q. Assertion (A): In circular waveguide the attenuation of TE01 mode decreases as the operating frequency increases.

Reason (R): The wall currents in a circular waveguide in TEQ1 mode are completely circumferential.

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Q. Consider the following statements

1. Usable bandwidth of ridge wave guide is more than that of rectangular waveguide.
2. For a given value of TM₁₀ cutoff frequency the cross section of ridge wave guide is lesser that that of rect angular waveguide.
3. Ridge wave guide has higher conductor losser than a rectangular waveguide.
4. Ridge guide has higher conductor losser than a rectangular waveguide.

Which of the above statements are correct?

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Q. Directive gain of elementary doublet is

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Q. A directional coupler is used

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Q. Assertion (A): In rectangular waveguide TE₀₁ mode is just TE₁₀ mode rotated by 90°.

Reason (R): When a rectangular waveguide is rotated by 90°, the broad and narrow dimensions get interchanged.

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Q. Consider the following statements about a magic tee

1. The collinear arms are isolated from each other.
2. On of the collinear arms is isolated from E arm.
3. On of the collinear arms is isolated from H arm.
4. E and H arms are isolated from each other.

Of the above statements

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Q. Assertion (A): Hollow waveguides are frequently used as transmission lines at microwave frequencies.

Reason (R): Waveguide has high power handling capacity, low loss and simple structure.

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Q. In π mode of operation of magnetron the spikes due to phase focussing effect rotate at an angular velocity corresponding to

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Q. In rectangular waveguides the ratio of width to height is about

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Q. Which of these statements is correct?

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Q. A rectangular waveguide has width a. Then at the cutoff frequency (with corresponding wave length λc)

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Q. Ridge waveguide is essentially a form of capacitively loaded guide.

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Q. In a rectangular waveguide

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Q. Which of the following modes cannot exist in rectangular resonant cavity?

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Q. 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

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