Equation of a plane progressive wave is given by `y=0.6 sin 2pi(t-(x)/(2)).` On reflection from a denser medium, its amplitude becomes `2//3` of the amplitude of the incident wave. The equation of the reflected wave is

Options

A. `y=0.6 sin 2pi(t+(x)/(2))`
B. `y=-0.4 sin 2pi(t+(x)/(2))`
C. `y=0.4 sin 2pi(t+(x)/(2))`
D. `y=-0.4 sin 2pi(t-(x)/(2))`

Answer

B

Explanation

On reflection from a denser medium, there is a phase reversal of `180^(@)`.
New amplitude `=(2)/(3)xx0.6=0.4`
`:.` Equation of reflected wave is `y=0.4sin 2pi[t+(x)/(2)+180^(@)]=-0.4sin2pi(t+x//2)`