A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at distance of 2 m and 3 m respectively from the source. The ratio of the intensities of the waves at P and Q is

Step-by-step solution

The average power per unit area that is incident perpendicular to the direction of propagation is called the intensity. Intensity of sound I= P 4 r^2 or, I 1 r^2 or, I₁ I₂ = ( r₂ r₁ )^2 here, r₁=2 ~m , r₂=3 ~m Substituting the values, we have I₁ I₂ = ( 3 2 )^2= 9 4