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24-Ruby IV
April 27, 2023
Question

dB

  • April 27, 2023
  • 1 reply
  • 2643 views

It is necessary to express the power of the power plant in decibels.
I go online and find out that bel is the decimal logarithm of the ratio of two physical quantities, the second of which (the denominator of the fraction) is called a certain base. In the same place on the Internet you can find the corresponding formula for the calculation.
Here's how such a calculation might look like in Mathcad 15 with the help of tools for separating variable and function names into styles using different font colors (black, green, blue and white - invisible).
If one watt is taken as the base, then the power of the largest Russian thermal power plant, Surgutskaya GRES-2, will be 96.812 decibels (see please the picture and the attach).

dB-1.png

We solve the inverse problem: given the power in decibels, it is necessary to calculate the power in the usual watts.

dB-2.png

Question. Why are decibels called decibels and not decabels? After all, if we multiply the logarithm by ten, and not by one tenth.

 

See please also decibel 

 

1 reply

23-Emerald IV
April 27, 2023

Answer is simple.

How do you get from 1 metre to decimeters? By multiplying the amount in metres with 10.

1 m = 10 dm

likewise:

1 B is  10 dB

 

Success!
L:uc

24-Ruby IV
April 27, 2023

Thank you Luc  for lifting a burden from my soul!

But

1 dB is 0.1 B

23-Emerald IV
April 27, 2023

Correct.

1 db = 0.1 B

Multiply each side of the equation with 10, you get:

10 dB = 1 B

Thus: 1 B is 10 dB.

 

Success!
Luc