Of the following,the one which emits a sound of higher pitch is:

$A$ small speaker delivers $2\, W$ of audio output. At what distance from the speaker will one detect $120\, dB$ intensity sound in $cm$?

The intensity level due to two waves of the same frequency in a given medium are $1 \, bel$ and $5 \, bel$. Then the ratio of amplitudes is

The power of sound from the speaker of a radio is $20 \text{ mW}$. By turning the knob of the volume control,the power of the sound is increased to $400 \text{ mW}$. The power increase in decibels as compared to the original power is ..... $dB$.

In a harmonium,the intermediate notes between a note and its octave form:

How many times more intense is $90\, dB$ sound than $40\, dB$ sound?