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

(1) 9 : 4

(2) 2 : 3

(3) 3 : 2

(4) 4 : 9

(1) Intensity $\propto \frac{1}{{\text{(Distance)}}^{\text{2}}}$

$\frac{{I}_{1}}{{I}_{2}}={\left(\frac{{d}_{2}}{{d}_{1}}\right)}^{2}={\left(\frac{3}{2}\right)}^{2}=\frac{9}{4}$.

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