Electronics and Communication Engineering - Exam Questions Papers - Discussion

4. 

A rectangular waveguide, in dominant TE mode, has dimensions 10 cm x 15 cm. The cut off frequency is

[A]. 10 GHz
[B]. 1 GHz
[C]. 15 GHz
[D]. 25 GHz

Answer: Option B

Explanation:

For TE10 mode


Vasundhara said: (Aug 16, 2014)  
In general dimensions of rectangle are represented as l:b. So a = 10cm, but here they have considered a = 15cm. Can any one help me to understand this?

Alok said: (Apr 13, 2015)  
Answer will be 1.5 GHz.

For TE mode we will consider a = 10 cm and f= (3*10^10) / (2*a (cm)).

Santhosh said: (Apr 5, 2016)  
Please explain clearly. I can't understand.

Gopal said: (Sep 19, 2016)  
@Alok.

I agree with your answer.

For Dominant mode TE10.
Cutoff frequency f = c/2a.
Put all the value and we get our answer.

Gauri said: (Jan 20, 2018)  
Yes, answer should be 1.5 GHz.

Rajesh said: (Feb 24, 2018)  
Dominant mode is TE10 only when dimensions are a>b but here in the question he gave a<b so dominant mode will be TE01 so Cut-off frequency is C/(2b).

Navya Rekha said: (Mar 23, 2018)  
@Gauri.

Here a is wider band& b is narrow band means a=15,b=10.
So,f=3*10^8 m/2*15 cm,
3*10^8/0.3=1ghz.

Thenmozhi said: (Nov 20, 2018)  
@Gopal.

What is "c" here?

Post your comments here:

Name *:

Email   : (optional)

» Your comments will be displayed only after manual approval.