If the separation between the screen and the source is increased by $2\%$,what would be the effect on the intensity?

The intensity level at a distance of $200 \ cm$ from a sound source is $80 \ dB$. If there is no loss of acoustic power in the air and the threshold intensity of hearing is $10^{-12} \ W/m^2$,what is the intensity level at a distance of $400 \ cm$ from the source (in $dB$)?

Two waves are represented by
$y_1 = 5 \sin 2 \pi(75 t - 0.25 x)$
$y_2 = 10 \sin 2 \pi(150 t - 0.50 x)$
The intensity ratio $\frac{I_1}{I_2}$ of the two waves is

With the propagation of a longitudinal wave through a material medium,the quantities transmitted in the propagation direction are

$A$ point source emits sound equally in all directions in a non-absorbing medium. Two points $P$ and $Q$ are at a distance of $9 \ m$ and $25 \ m$ respectively from the source. The ratio of the amplitudes of the waves at $P$ and $Q$ is

If the ratio of the amplitude of two waves is $4 : 3$,then the ratio of their maximum and minimum intensity will be: