Q.

The amplitude and phase of a wave that is formed by the superposition of two harmonic travelling waves, y1(x,t)=4 sin (kxωt) and y2(x,t)=2 sin (kxωt+2π3), are: (Take the angular frequency of initial waves same as ω)          [2025]

1 [6,2π3]  
2 [6,π3]  
3 [3,π6]  
4 [23,π6]  

Ans.

(4)

A=A12+A22+2A1A2 cos ϕ

Here, ϕ=2π3

A=42+22+2×4×2 cos 2π3=23

tan α=2 sin ϕ4+2 cos ϕ=13 α=π/6