What do u mean by this question? - Decibels

[zahrein]

what do u mean? in japanese

Calculate Multiple value for -20dB, -12dB, - 10dB, -3dB, 0dB, 3dB, 4dB, 6dB, 12dB.
Calculate in dB for multiple values 1,10,100,1000,10000,100000.


I dont undersatnd the meaning of calculate the multiple ?

Can give a any examples?

 

[xvibe]

Well, I think that is for you to see how dBs and linear values works. Let's see:
Where is to calculate the multiple values for 1, 10, 100,1000,10000,100000 you get in dBs 0, 1, 2, 3, 4 and 5. That is, where in linear values there's a multipling factor of 10 in each value in dBs there's is only an increment factor of 1 respectively to each number in linear.
For the first question it's the same, you get in linear values: 0.01, 0.06, 0.1, 0.5, 1, 2, 2.5, 4, 15.8 . Where you see that each increment of 3dB equals to doubling the power.
I hope that this was useful!

 

[brmadhukar]

I guess it should be dBm, dBW sort. The same number has different dB values.
Hope it helps

 

[springf2000]

db is a widely used in the telcommunication,fro example we use the -80dBC/Hz@100k express noise phase,but it has th unit, if no unit ,i canot understand y what y said

 

[defnfo]

dB value = 10*lg(Multiple value ) for power
dB value = 20*lg(Multiple value ) for voltage

 

[djalli]

Calculate Multiple value for -20dB, -12dB, - 10dB, -3dB, 0dB, 3dB, 4dB, 6dB, 12dB.

I dont undersatnd the meaning of calculate the multiple ?
Can give a any examples?

Your example:
-20dB is 10^(-20/10)=0.01Watts=10mWatts

Now you shall see unit dB and dBm:
I can say -20dB or I can say 10dBm. It is the same power. See example below and try all yours numbers.

dBm is power in MiliWatts.
30dBm = 10^(30/10)=1000mW=1 Watt

but 30dB = 10^(30/10)=1000 Watts

DeciBel is for the name of Alexander Bell and Deci=10 unit of tens
I dont know but egnineers are very used to dB units. It simplifies addition and substraction I guess.

djalli.