$A$ plane progressive wave propagating along the positive $x$-axis is represented by:

The diagram shows the propagation of a progressive wave. $A$,$B$,$C$,$D$,$E$,and $F$ are points on this wave. Which of the following points are in the same state of vibration (i.e.,in the same phase)?

The diagram below shows an instantaneous position of a string as a transverse progressive wave travels along it from left to right. Which one of the following correctly shows the direction of the velocity of the points $1, 2$ and $3$ on the string?

$y=3 \sin \pi\left(\frac{t}{2}-\frac{x}{4}\right)$ represents an equation of a progressive wave,where $t$ is in $s$ and $x$ is in $m$. The distance travelled by the wave in $5 \,s$ is (in $\,m$)

The equation of a progressive wave is given by $y = A \cos 240(t - x/12)$,where $t$ is the time in seconds and $x$ is the distance in meters. The phase difference (in radians) between two positions $0.5 \, m$ apart is:

Given below are some functions of $x$ and $t$ to represent the displacement (transverse or longitudinal) of an elastic wave. State which of these represent a travelling wave.