The cut off wavelength in circular waveguide guide diameter square of guide diam

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Question
The cut off wavelength in circular waveguide
Options
A. guide diameter
B. square of guide diameter
C. cube of guide diameter
D. square root of guide diameter

Correct Answer

guide diameter

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 directivity in a receiving antenna
1. increases the intercept area in forward direction
2. reduces the noise picked up from other sources
3. provides a means of discriminating against undesired signals originating in directions other than in which the desired transmitter lies.
Which of the above statements are correct?
Options
A. 1 only
B. 1 and 2 only
C. 1, 2 and 3
D. 2 and 3 only

2. A loss less line is terminated in a circular lines are E lines
Options
A. SWR = 0
B. SWE = 0
C. SWR is finite
D. SWR = ?

3. A magnetron has a cylindrical cathode surrounded by an anode structure having cavities opening into interaction space by means of slots
Options
A. True
B. False

5. Assertion (A): PIN diode can be used as attenuator and limiter.
Reason (R): PIN diode has a thin intrinsic layer.
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

6. In a TWT the axial component of electric field advances along the tube
Options
A. at a velocity that is almost equal to speed of light
B. at a velocity that is a small fraction of speed of light
C. at a velocity that is about 50% of speed of light
D. at a velocity that may be even more than speed of light

7. The directive gain of a transmitting antenna is
Options
A. proportional to wavelength
B. inversely proportional to wavelength
C. proportional to square of wavelength
D. inversely proportional to square of wavelength

8. A transmission line has Z₀ = 300 ? and Z_L = (300 - j300) ohm. The transmission coefficient is
Options
A. 1.265 ? - 18.43�
B. 1.01 ? - 10�
C. 1.14 ? 66.68�
D. 1.09 ? 66.68�

10. Assertion (A): A half wavelength line can be used as a 1 : 1 transformer.
Reason (R): The input impedance of a half wavelength line is equal to load impedance.
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

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