In a circular waveguide the dominant mode is TE01 TE11 TE20 TE21 Some applicatio

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Question
In a circular waveguide the dominant mode is
Options
A. TE₀₁
B. TE₁₁
C. TE₂₀
D. TE₂₁

Correct Answer

TE₁₁

Explanation

Some applications require dual polarization capability. Circular waveguide has this capability.

These analysis uses cylindrical coordinates.

In circular waveguide TE₁₁ mode has the lowest cut off frequency and is the dominant mode.

If D is diameter of waveguide

?_c = 1.706 D for TE₁₁ mode

?_c = 1.029 D for TE₂₁ mode

?_c = 0.82 D for TE₀₁ mode

?_c = 1.306 D for TM₀₁ mode.

Microwave Communication problems

Search Results

1. The diagram to show distance time history of electrons in klystron amplifier is called
Options
A. apple gate diagram
B. asynchronous diagram
C. bunching diagram
D. velocity modulation diagram

3. The velocity factor of a transmission line depends on
Options
A. temperature
B. skin effect
C. relative permittivity of dielectric
D. none of the above

4. Assertion (A): A backward wave oscillator has an internal positive feedback.
Reason (R): A positive feedback is necessary for sustained oscillations.
Options
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

5. A resistive microwave load with Z_L = 150 ? is connected to 50 ? coaxial line. SWR is
Options
A. more than 3
B. less than 3
C. equal to 3
D. either (a) or (c)

6. In a travelling wave tube distributed interaction between an electron beam and a travelling wave takes place
Options
A. True
B. False

7. In a klystron amplifier dc electron velocity is v₀ and dc electron charge density is r₀ the dc beam current is
Options
A. r₀v₀
B. r₀^/v₀
C. v₀^/r₀
D. (v₀^/r₀)²

8. 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.
Options
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

9. A loss less line of characteristic impedance Z₀ is terminated in pure reactance of -jZ₀ value. VSWR is
Options
A. 10
B. 2
C. 1
D. infinity

10. In a directional coupler
Options
A. isolation (dB) equals coupling plus directivity
B. coupling (dB) equals isolation plus directivity
C. directivity (dB) equals isolation plus coupling
D. isolation (dB) equals (coupling) (directivity)

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