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

Noise level will be -18.2 watt

So option (b) will be correct answer

Step-by-step explanation:

We have given sound intensity
`I=1.5* 10^(-14)w/m^2`

And threshold intensity
`I_0=* 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(I)/(I_0)=10log(1.5* 10^(-14))/(10^(-12))=10log0.015-18.23`

So the noise level will be -18.2

So option (b) will be correct answer