Electrical Engineering - Passive Filters - Discussion

Discussion :: Passive Filters - General Questions (Q.No.16)

16. 

At a certain frequency, the output voltage of a filter is 6 V and the input is 12 V. The voltage ratio in decibels is

[A]. 6.02 dB
[B]. –6.02 dB
[C]. 12.04 dB
[D]. –12.04 dB

Answer: Option B

Explanation:

No answer description available for this question.

Jill Scar said: (Oct 10, 2015)  
Why is it negative?

Pavithra said: (Oct 14, 2015)  
Always the ratio is first output voltage (6) then input voltage (12) that's why it is negative.

Shan said: (Nov 27, 2015)  
Wrong @Pavithra that negative due to we convert into the decibel scale.

Sudhir said: (Apr 11, 2016)  
Use this formula to convert the voltages to decibels:

20 * Log (Vout / Vin) = dB.

Shafi said: (Mar 14, 2017)  
How to calculate decibel values without calci?

Can anyone suggest me.

Suma said: (Jun 12, 2017)  
Here, 20log(Vout/Vin) = 20log (6/12) = -6.02dB.

Sushma said: (Jun 27, 2019)  
Please, can anyone tell how to calculate dB and why it is negative?

Majid Mahmood said: (Aug 19, 2019)  
Db = 20logvout/vin so 20(log6/12) = 20 * (-0.3010) = -6.02db.

Post your comments here:

Name *:

Email   : (optional)

» Your comments will be displayed only after manual approval.