A sound wave travels from air into water. Which of the following properties of the wave remains unchanged?

Sound waves of wavelength greater than that of audible sound are called

A point source emits sound equally in all directions in a non-absorbing medium. Two points $P\,\,and\,\,Q$ are at distance of $2{\mkern 1mu} \,\,m\,\,and\,\,3{\mkern 1mu} {\mkern 1mu} \,m$ respectively from the source. The ratio of the intensities of the waves at $P\,\,and\,\,Q$ is

A sound absorber the sound level by $20\,\,dB$. The intensity decreases by a factor of

Intensity level $200\,\,cm$ from a source of sound is $80\,\,dB$. If there is no loss of acoustic power in air and intensity of threshold hearing is ${10^{ - 12}}\,\,W\,\,{m^{ - 2}}$ then, what is the intensity level at a distance of $4000\,\,cm$ from source

In a resonance tube, using a tuning fork of frequency $325\,\,Hz$, two successive resonance length are observed as $25.4\,\,cm$ and $77.4\,\,cm$ respectively. The velocity of sound in air is

The distance between two consecutive crests in a wave train produced in a string in $5\,\,cm$. If $2$ complete waves pass through any point per second, the velocity of the wave is

If length of stretched string is increased by 50% keeping mass per unit length same, then in order to keep its frequency of vibration constant, its tension must be increased by

Sound travels faster in humid air than in dry air. This is primarily because:

A closed organ pipe resonates at a fundamental frequency of 256 Hz. What is the length of the pipe if the speed of sound in air is 340 m/s?

Two sound waves of equal amplitude and slightly different frequencies $f_1$ and $f_2$ are travelling in the same direction. The time interval between successive maxima of intensity is: