A wave `y = a sin (omegat - kx)` on a string meets with another wave producing a node at `x = 0`. Then the equation of the unknown wave is

Options

A. `y=asin(omegat+kx)`
B. `y=-asin(omegat+kx)`
C. `y=asin(omegat-kx)`
D. `y=-sin(omegat-kx)`

Answer

B

Explanation

Here, stationary wave is formed, since node is formed at `x=0`. Therefore, the poing `x=0` is a fixed point `(i.e.,` it acts as a denser medium ) for a reflected wave.
When reflectio of a wave takes place from denser medium, it is with a change in phase by `pi` rad. without any change in type of wave . The distance `x` of the particle will be taken as `-x` in the reflected wave with additional phase of `pi ` radian. Thus equation of reflected wave
`y=asin (omegat=kx+pi)=-asin (omegat +kx)`