Due to a point isotropic sonic source, loudness at a point is `L=60dB` If density of air is `rho=((15)/(11))(kg)/(m^3)` and velocity of sound in air is `v=33(m)/(s)`, the pressure oscillation amplitude at the point of observation is `[I_0=10^-12(W)/(m^2)`]A. `0.3(N)/(m^2)`B. `0.03(N)/(m^2)`C. `3xx10^-3(N)/(m^2)`D. `3xx10^-4(N)/(m^2)`

Due to a point isotropic sonic source, loudness at a point is `L=60dB`

1.	Due to a point isotropic sonic source, loudness at a point is `L=60dB` If density of air is `rho=((15)/(11))(kg)/(m^3)` and velocity of sound in air is `v=33(m)/(s)`, the pressure oscillation amplitude at the point of observation is `[I_0=10^-12(W)/(m^2)`]A. `0.3(N)/(m^2)`B. `0.03(N)/(m^2)`C. `3xx10^-3(N)/(m^2)`D. `3xx10^-4(N)/(m^2)`
Answer» Correct Answer - B `60dB=10dBlog((I)/(I_0))` `impliesI=(10^6xx10^-12)(W)/(m^2)=10^-6(W)/(m^2)` `[I_0=10^-12(W)/(m^2)]` `I=((triangleP_m)^2)/(2rhov)` where `rho=(15)/((11kg)/(m^3))`,`v=330(m)/(s)` `(triangleP_m)^2=2rhovI=2xx(15)/(11)xx330xx10^-6` `impliestriangleP_m=0.03(N)/(m^2)`

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