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IIT Entrance GATE
3 followers 20 Jun 2024 02:42 PM

In a klystron amplifier dc electron velocity is v0 and dc electron charge density is r0 the dc beam current is

A

r0v0

B

r0/v0

C

v0/r0

D

(v0/r0)2

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3 followers 20 Jun 2024 02:41 PM

A waveguide section in a microwave circuit acts as

A

LP filter

B

Bandpass filter

C

HP filter

D

Band stop filter

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3 followers 20 Jun 2024 01:34 PM

In a turnstile antenna two-half wave resonant wire radiators are placed at 90° to each other in the same plane and are excited

A

in phase

B

in phase opposition

C

90° out of phase with each other

D

45° out of phase with each other

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3 followers 19 Jun 2024 11:24 AM

Which of the following devices uses a slow wave structure?

A

Klystron two cavity amplifier

B

Klystron multicavity amplifier

C

Reflex klystron oscillator

D

TWT

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3 followers 19 Jun 2024 11:23 AM

A resistive microwave load with ZL = 150 Ω is connected to 50 Ω coaxial line. SWR is

A

more than 3

B

less than 3

C

equal to 3

D

either (a) or (c)

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3 followers 19 Jun 2024 11:22 AM

Which TM mode in rectangular waveguide has lowest cutoff frequency?

A

TM11

B

TM01

C

TM10

D

TM21

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3 followers 18 Jun 2024 10:43 AM

A matched generator (Zg = Z0) with 1 Ω available. If all ports are matched, the power delivered at ports 1, 2, 3 respectively are

A

0.5 W, 0.5 W, 0 W

B

0 W, 0 W, 1 W

C

0.33 W each

D

0 W, 0.25 W, 0.25 W

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3 followers 18 Jun 2024 10:36 AM

A 10 km long line has a characteristic impedance of 400 ohms. If line length is 100 km, the characteristic impedance is

A

4000 Ω

B

400 Ω

C

40 Ω

D

4 Ω

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3 followers 18 Jun 2024 10:35 AM

Reflex klystron oscillator is essentially a low power device

A

True

B

False

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3 followers 17 Jun 2024 03:22 PM

Assertion (A): A coaxial line is a non-radiating line.Reason (R): In a coaxial line the electric and magnetic fields are confined to the region between the concentric conductors.

A

Both A and R are correct and R is correct explanation of A

B

Both A and R are correct but R is not correct explanation of A

C

A is correct but R is wrong

D

A is wrong but R is correct

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3 followers 17 Jun 2024 03:21 PM

A line is excited by a 100 V dc source. If reflection coefficients at both ends are 1 each then

A

there will be no oscillations on line

B

there will be only 1 or 2 oscillations on line

C

there will be a finite number of oscillations on line

D

the oscillations will continue indefinitely

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3 followers 17 Jun 2024 03:21 PM

In a backward wave oscillator the wave travelling along the line winds itself back and forth

A

True

B

False

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3 followers 14 Jun 2024 11:01 AM

Assertion (A): Artificial transmission lines are frequently used in laboratories.Reason (R): An artificial transmission line can be used to represent an actual line and can also be used as a delay circuit, as attenuator, as filter network etc.

A

Both A and R are correct and R is correct explanation of A

B

Both A and R are correct but R is not correct explanation of A

C

A is correct but R is wrong

D

A is wrong but R is correct

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3 followers 14 Jun 2024 10:59 AM

In the given figure the reflection coefficient at source end is

A

1

B

-1

C

1/3

D

-1/3

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3 followers 14 Jun 2024 10:56 AM

The action of backward wave oscillator is similar to that of

A

klystron amplifier

B

reflex klystron oscillator

C

TWT

D

magnetron

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3 followers 13 Jun 2024 11:42 AM

The fabrication of microstrip line is done by

A

photo etching

B

printed circuit technique

C

oxidation

D

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3 followers 13 Jun 2024 11:41 AM

In a travelling wave tube distributed interaction between an electron beam and a travelling wave takes place

A

True

B

False

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3 followers 13 Jun 2024 11:41 AM

For a 50 Ω resistor for 3 GHz application, the stray capacitance should be less than

A

1 μF

B

1 nF

C

1 pF

D

0.1 pF

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3 followers 12 Jun 2024 11:47 AM

In the given figure the time taken by the wave to make one round trip is

A

10 ns

B

20 ns

C

30 ns

D

40 ns

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3 followers 12 Jun 2024 11:17 AM

A line has a phase constant of 29.8 rad/m. At 1000 MHz the wavelength is

A

29.8 m

B

2.98 m

C

2.1 m

D

0.21 m

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