A wave representing by the equation `y = a cos(kx - omegat)` is superposed with another wave to form a stationary wave such that `x = 0` is a node. The equation for the other wave is

Options

A. `a sin(kx + omegat)`
B. `-a cos(kx - omegat)`
C. `-a cos(kx + omegat)`
D. `-a sin(kx - omegat)`

Answer

C

Explanation

Note : Stationary wave is produced when two waves travel in opposite direction.
Now, `y = a cos(kx - omegat) - a cos(kx + omegat)`
:. `y = 2a sin kx sin omegat` is equation of stationary wave which gives a node at `x = 0`.