$A$ wave is represented by $x = 4 \cos \left(8t - \frac{y}{2}\right)$,where $x$ and $y$ are in $m$ and $t$ is in $s$. The frequency of the wave (in $s^{-1}$) is .........

The figure represents the instantaneous picture of a longitudinal harmonic wave travelling along the negative $x$-axis. Identify the correct statement$(s)$ related to the movement of the points shown in the figure. The points with maximum displacement are:

Two waves are represented by the equations $y_1 = a \sin \omega t$ and $y_2 = a \cos \omega t$. The first wave is .....

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

$A$ wave motion has the function $y = a_0 \sin(\omega t - kx)$. The graph in the figure shows how the displacement $y$ at a fixed point varies with time $t$. Which one of the labelled points shows a displacement equal to that at the position $x = \frac{\pi}{2k}$ at time $t = 0$?

When a wave enters into a rarer medium from a denser medium,the property of the wave which remains constant is