Which of the following travelling wave will produce standing wave , with nodes at `x = 0`, when superimosed on ` y = A sin ( omega t - kx)`

Options

A. `A sin ( omega t + kx)`
B. `A sin ( omega t + kx + pi)`
C. `A cos (omega t + kx)`
D. `A cos ( omega t + kx + pi)`

Answer

B

Explanation

Substituting ` x = 0 `, we have given wave `y = A sin omega t ` at ` x = 0` other should have ` y = - A sin omega t` equation so displacement may be zero at all the time . Hence , option (b) is correct.