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.

More questions

1. The power requirements of a DRAM in active and stand by modes is about
Options
A. 350 mW and 5 mW respectively
B. 350 mW each
C. 5 mW each
D. 350 mW and 100 mW respectively

2. The different access methods which permit many satellite users to operate in parallel through a single transponder without interfering with each other as
Options
A. Frequency Division Multiple Access (FDMA)
B. Time Division Multiple Access (TDMA)
C. Code Division Multiple Access (CDMA)
D. All of the above

3. Match the following:

	List I		List II
A.	T (Reflection coefficient) = 0	1.	(Z_L - Z_o)/(Z_L + Z_o)
B.	T = - 1	2.	Z_L = Z_o
C.	T = + 1	3.	Z_L = 0
D.	- 1 < T < + 1	4.	Z_L = ?

Options
A. A-2, B-3, C-4, D-1
B. A-2, B-4, C-1, D-3
C. A-1, B-2, C-3, D-4
D. A-3, B-2, C-4, D-1

4. Assertion (A): Ferromagnetic materials possess ferromagnetic properties only when temperature is less than paramagnetic curie temperature.
Reason (R): For a ferromagnetic material for T > ?_f.
Options
A. Both A and R are true and R is correct explanation of A
B. Both A and R are true but R is not correct explanation of A
C. A is true but R is false
D. A is false but R is true

6. A two branch parallel circuit has a 20 ? resistance and 1 H inductance in one branch and a 100 ?F capacitor in the second branch. It is fed from 100 V ac supply, at resonance, the input impedance of the circuit is
Options
A. 500 ?
B. 50 ?
C. 20 ?
D. 5 ?

8. An amplifier has a large ac input signal. The clipping occurs on both the peaks. The output voltage will be nearly a
Options
A. sine wave
B. square wave
C. triangular wave
D. (a) or (c)

9. In the figure shown, A₁, A₂, A₃ are identical Ammeters. If A₁ and A₃ read 5 and 13 A respectively, reading of A₂ will be
Options
A. 8
B. 13 A
C. 18
D. 12 A

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