Highly selective Backlog Qs for JEE MainPhysicsWaves and Sound
Two harmonic travelling waves are described by the equations y 1 = a sin k x - ω t and y 2 = a sin - k x + ω t + ϕ The amplitude of the superposed wave is
Options
- A2 a cos ϕ 2
- B2 a sin ϕ
- C2 a cos ϕ
- D2 a sin ϕ 2
Correct answer
D. 2 a sin ϕ 2
Step-by-step solution
y 1 = a sin k x - ω t                   . . . 1 y 2 = a sin - k x + ω t + ϕ                     . . . 2 On adding 1 and 2 , y 1 + y 2 = 2 asin k x - ω t + - k x + ω t + ϕ 2 cos k x - ω t + k x - ω t - ϕ 2 = 2 asin ϕ 2 cos 2 ( k x + ω t ) - ϕ 2 Amplitude, A ϕ is a function of phase difference ϕ between constituent of waves ∴       &#