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

Which of the following equations represents a travelling wave?

In a sine wave,what is the minimum distance between two particles that always have the same speed?

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

$A$ travelling harmonic wave is represented by the equation $y(x, t) = 10^{-3} \sin(50t + 2x)$,where $x$ and $y$ are in meters and $t$ is in seconds. Which of the following is a correct statement about the wave?

The equation of wave motion is $Y = 6 \sin (12\pi t - 0.02\pi x + \pi/3)$ where $x$ is in metre and time in second. The velocity of the wave is (in $\text{ m/s}$)