Which one of the following statements is true?

Which of the following statements is/are correct.

1. (a), (b) and (d)
2. (b) and (d)
3. (a), (c) and (d)
4. All are correct

The displacement of a particle is given by $y=5\times {10}^{-4}\sin (100t-50x)$, where x is in metres and t is in seconds. The velocity of the wave is:

1. 5000 m/sec

2. 2 m/sec

3. 0.5 m/sec

4. 300 m/sec

The equation \(y(x,t) = 0.005 ~cos (\alpha x- \beta t)\) describes a wave traveling along the x-axis. If the wavelength and the time period of the wave are 0.08 m and 2.0 s, respectively, then $\mathrm{\alpha }$ and $\mathrm{\beta }$ in appropriate units are:

1. $\mathrm{\alpha }=25.00$ $\mathrm{\pi },$ $\mathrm{\beta }=\mathrm{\pi }$

2. $\mathrm{\alpha }=\frac{0.08}{\mathrm{\pi }},$ $\mathrm{\beta }=\frac{2.0}{\mathrm{\pi }}$

3. $\mathrm{\alpha }=\frac{0.04}{\mathrm{\pi }},$ $\mathrm{\beta }=\frac{1.0}{\mathrm{\pi }}$

4. $\mathrm{\alpha }=12.50$ $\mathrm{\pi },$ $\mathrm{\beta }=\frac{\mathrm{\pi }}{2.0}$

If a travelling wave pulse is given by $\mathrm{y}=\frac{20}{4+{(\mathrm{x}+4\mathrm{t})}^{\mathrm{2 }}}$(m), then:

The equation of a progressive wave is given by $y=4\sin \left\{\pi \left(\frac{{\displaystyle t}}{{\displaystyle 5}}-\frac{{\displaystyle x}}{{\displaystyle 9}}\right)+\frac{{\displaystyle \pi }}{{\displaystyle 6}}\right\}$.
Which of the following is correct​​​​?
1. v = 5 m / sec
2.  λ = 18 m
3.  a = 0.04 m
4.  n = 50 Hz

A wave traveling in the +ve x-direction having maximum displacement along y-direction as 1 m, wavelength $2\pi$ $m$ and frequency of $\frac{1}{\mathrm{\pi }}$ Hz, is represented by:

$1.$ $y=\sin \left(2\pi x-2\pi t\right)$

$2.$ $y=\sin \left(10\pi x-20\pi t\right)$

$3.$ $y=\sin \left(2\pi x+2\pi t\right)$

$4.$ $y=\sin \left(x-2t\right)$

If a wave is travelling in a positive X-direction with A = 0.2 m, velocity = 360 m/s, and λ = 60 m, then the correct expression for the wave will be: