The amplitudes of two waves are in the ratio $5 : 2$. If all other conditions for the two waves are the same,what is the ratio of their energy densities?

$A$ stationary point source of sound emits sound uniformly in all directions in a non-absorbing medium. Two points $P$ and $Q$ are at a distance of $4 \ m$ and $9 \ m$ respectively from the source. The ratio of amplitudes of the waves at $P$ and $Q$ is

$A$ musical instrument $P$ produces sound waves of frequency $n$ and amplitude $A$. Another musical instrument $Q$ produces sound waves of frequency $n/4$. The waves produced by $P$ and $Q$ have equal energies. The amplitude of waves produced by $Q$ will be

$A$ travelling wave is partly reflected and partly transmitted from a rigid boundary. Let $a_i, a_r$ and $a_t$ be the amplitudes of the incident wave,reflected wave,and transmitted wave,and $I_i, I_r$ and $I_t$ be the corresponding intensities. Choose the correct alternative.

The amplitude of a wave at a distance $r$ from a point source is $A$. What will be the amplitude at a distance $2r$ from the source?

The sound intensity level at a point $4 \,m$ from the point source is $10 \,dB$. Then the sound level at a distance $2 \,m$ from the same source will be ........ $dB$.