Understanding of technical terms

[imranahmed]

Please let me know that how to understand dB (decibel)?

In my knowledge,the decibel shows how much power loss or gain,is it right or wrong?

Please can anyone interested to tell me?

 

[kripacharya]

dB is always the ratio of two numbers, except that after taking the ratio, then you also do logarithm of that ratio. then you get answer in B. since B is a big ratio, we use a smaller unit which is 1/10th the size, which is dB or deci - bel. deci- means 1/10th. it is like Meter and centi-Meter, where centi- means 1/100th

so yes, it can be used for any ratio, and power loss or gain is also a ratio.

like if input power is ( e.g. ) 10 watts, and output power is 20 watts, then the ratio is --

20 / 10 = 2

now take log (base10) of 2 --> 0.301 Bells
and multiply x10 --> 3.01 deciBells

so your amp is said to have a gain of 3 db

 

[tpetar]

https://en.wikipedia.org/wiki/Decibel