The pressure amplitude in a sound wave from a radio receiver is `2.0xx10^-2 Nm^-2` and the intensity at a point is `5.0xx10^-7Wm^-2.` If by turning the volume knob the pressure amplitude is increased to `2.5xx10^-2Nm^-2` evaluate intensity.

Explanation

The intensity is proportioN/Al to the square of the presue amplitude.
`Thus, I'/I=(p'_0/p_0)^2`
`or I'=(p'_0/p_0)^2I=(2.5/2.0)62xx5.0x10^-7Wm^2`
`=7.8xx10^-7Wm^-2.`