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

$A$ musical instrument $P$ produces sound waves of frequency $n$ and amplitude $A_P$. Another musical instrument $Q$ produces sound waves of frequency $\frac{n}{4}$. The waves produced by $P$ and $Q$ have equal energies. If the amplitude of waves produced by $P$ is $A_P$,the amplitude of waves produced by $Q$ will be: (in $A_P$)

$A$ 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

The ratio of intensities of two waves is given by $4:1$. The ratio of the amplitudes of the two waves is

$A$ point source is emitting sound waves of intensity $16 \times 10^{-8} \text{ W m}^{-2}$ at a distance of $1 \text{ m}$ from the source. The difference in intensity (magnitude only) at two points located at distances of $2 \text{ m}$ and $4 \text{ m}$ from the source respectively will be . . . . . . $\times 10^{-8} \text{ W m}^{-2}$.

There is a long linear source of sound whose power is $P$ and length is $L$. At point $A$,the sound level is $80 \ dB$. Then at point $B$,the sound level will be .... $dB$.