$A$ wave on a string is travelling and the displacement of particles on it is given by $x = A \sin (2t - 0.1x)$. Then the wavelength of the wave is

$A$ sound wave of frequency $500 \text{ Hz}$ travels between two points $X$ and $Y$ separated by a distance of $600 \text{ m}$ in a time of $2 \text{ s}$. The number of waves between the points $X$ and $Y$ are

Given below are some functions of $x$ and $t$ to represent the displacement of an elastic wave.
$(i) \, y = 5 \cos (4x) \sin (20t)$
$(ii) \, y = 4 \sin (5x - t/2) + 3 \cos (5x - t/2)$
$(iii) \, y = 10 \cos (252\pi t) \cos (250\pi t)$
$(iv) \, y = 100 \cos (100\pi t + 0.5x)$
State which of these represent:
$(a)$ a travelling wave along $-x$ direction
$(b)$ a stationary wave
$(c)$ beats
$(d)$ a travelling wave along $+x$ direction.
Give reasons for your answers.

The equation of a travelling wave is $y = a \sin 2 \pi (p t - \frac{x}{5})$. Then the ratio of the maximum particle velocity to the wave velocity is ...........

$A$ progressive sound wave is represented by $y = a \sin(400\pi t - \pi x / 6.85)$,where $x$ is in $m$ and $t$ is in $s$. The frequency of the wave is .... $Hz$.

The equation of a wave is given by (all quantities expressed in $M.K.S.$ units) $Y = 5 \sin(10\pi t - 0.1\pi x)$ along the $x$-axis. The phase difference between two points separated by a distance of $10 \ m$ along the $x$-axis is: