Question

17. A microphone of surface area 2.0 cm’ absorbs 1.1 mW of sound. What is the intensity

Answer 1

Answer:

$I=0.055\ W/m^2$

Explanation:

Given that,

A microphone of surface area 2.0 cm’ absorbs 1.1 mW of sound.

Surfrace area, A = 2 cm = 0.02 m

Power absorbed, P = 1.1 mW = 0.0011 W

We need to find the intensity of sound hitting the microphone. Power per unit area is called the intensity of sound. It can be given by :

$I=\dfrac{P}{A}\\\\=\dfrac{0.0011\ W}{0.02\ m^2}\\\\=0.055\ W/m^2$

So, the intensity of sound is $0.055\ W/m^2$. Hence, the correct option is (b).