In a closed tube whose length can be altered by sliding one of the halves relative to other is shown in the figure. In the initial condition the detector detects minimum intensity. One of the tubes is then displaced by $5 \mathrm{cm}$, during this displacement detector detects maximum intensity for $10$ times and then a minimum intensity when the displacement is complete. What is the wavelength of sound?

In Quincke's tube experiment, the difference in amplitudes is due to

When beats are produced by progressive waves having the same amplitude and nearly the same frequency, the maximum loudness heard is

Two identical point-like sound sources emitting sound in same phase of wavelength $1 \mathrm{m}$ are located at points $P$ and $Q$ as shown in figure. All sides of the polygon are equal and of length $1 \mathrm{m}$. The intensity of sound at $M$ due to source $P$ alone is $I_0$. What will be the intensity of sound at point $M$ when both the source are on?

The sound signal is sent through a composite tube as shown in the figure. The radius of the semicircular portion of the tube is $r$. Speed of sound in air is $v$. The source of sound is capable of giving varied frequencies in the range of $v_1$ and $v_2$ (where $v_2>v_1$). If $n$ is an integer then frequency for maximum intensity is given by