$A$ sound wave of frequency $200 Hz$ is travelling in air. The speed of sound in the air is $340 m s^{-1}$. What is the phase difference at a given instant between two points separated by a distance of $85 cm$ along the direction of propagation?

The equation of a plane progressive wave is given by $y = 0.025 \sin (100t + 0.25x)$. The frequency of this wave would be

$A$ plane wave $y=a \sin (\omega t-k x)$ propagates through a stretched string. The particle velocity versus $x$ graph at $t=0$ is

When a wave travelling in a medium is reflected from the boundary of a denser medium,which of the following will not change?

The disturbance $y(x, t)$ of a wave propagating in the positive $x$-direction is given by $y = \frac{1}{1 + x^2}$ at time $t = 0$ and by $y = \frac{1}{1 + (x - 1)^2}$ at $t = 2 \ s$,where $x$ and $y$ are in meters. The shape of the wave disturbance does not change during the propagation. The velocity of the wave in $m/s$ is:

$A$ plane wave is described by the equation $y = 3 \cos \left( \frac{x}{4} - 10t - \frac{\pi}{2} \right)$. The maximum velocity of the particles of the medium due to this wave is