Question

A wave travelling in positive $X$-direction with $a=0.2\, mt$., velocity $=360 \,mt / \sec$. and $\lambda=60 \,mts$, then correct expression for the wave is

• A. $y=0.2 \sin \left[2 \pi\left(6 t+\begin{array}{c}x \\ 60\end{array}\right)\right]$
• B. $y=0.2 \sin \left[\pi\left(6 t+\frac{x}{60}\right)\right]$
• C. $y=0.2 \sin \left[2 \pi\left(6 t-\frac{x}{60}\right)\right]$
• D. $y=0.2 \sin \left[\pi\left(6 t-\frac{x}{60}\right)\right]$

Answer 1

Answer: (C)

The equation of progressive wave travelling in positive $x$-direction is given by
$y=a \sin \frac{2 \pi}{\lambda}(v t-x)$
Here $a=0.2 \,m , $
$v=360\, m / \sec , $
$\lambda=60\, m$
$\therefore y=0.2 \sin \frac{2 \pi}{60}(360 \,t-x) $
$=0.2 \sin \left[2 \pi\left(6 t-\frac{x}{60}\right)\right]$