The equation of a wave is given as $y = 0.07 \sin (12\pi x - 3000\pi t)$. Where $x$ is in $m$ and $t$ is in $s$,then the correct statement is:

What is the phase change of a wave when it reflects from a rigid support?

The frequency of the sinusoidal wave $y = 0.40\cos(2000t + 0.80x)$ is

Two waves of frequencies $20 Hz$ and $30 Hz$ travel out from a common point. The phase difference between them after $0.6 s$ is:

The equation of a wave is given by $y = 10 \sin \left(\frac{2 \pi t}{30} + \alpha\right)$. If the displacement is $5 \ cm$ at $t = 0 \ s$,then the total phase angle at $t = 7.5 \ s$ will be:

$A$ transverse sinusoidal wave of amplitude '$a$',wavelength $\lambda$,and frequency $f$ is travelling on a stretched string. The maximum speed at any point on the string is $v/10$,where $v$ is the speed of propagation of the wave. If $a = 10^{-3} \ m$ and $v = 10 \ ms^{-1}$,then $\lambda$ and $f$ are given by: