Question

Find the noise level of a sound having an intensity of 1.5x10^-14W/m^2 given I0=10^12 W/m2

20.5 dB

-18.2 dB

-17.6 dB

15.4 dB

Answer 1

Answer:

Noise level will be -18.2 watt

So option (b) will be correct answer

Explanation:

We have given sound intensity $I=1.5\times 10^{-14}w/m^2$

And threshold intensity $I_0=\times 10^{-12}w/m^2$ ( in question it is given as $10^{12}w/m^2$ but its standard value is $10^{-12}w/m^2$ )

Now noise level  $=10log\frac{I}{I_0}=10log\frac{1.5\times 10^{-14}}{10^{-12}}=10log0.015-18.23$

So the noise level will be -18.2

So option (b) will be correct answer