Question

Three transverse waves are represented by 

y₁ = A cos(kx - ωt)

y₂ = A cos(kx + ωt)

y₃ = A cos(ky - ωt)

The combination of waves which can produce stationary waves is 

(a) y₁ and y₂ 

(b) y₂ and y₃ 

(c) y₁ and y₃ 

(d) y₁ , y₂ and y₃

Answer 1

Correct option: (a) y₁ and y₂

Explanation: 

For producing stationary waves, the two transverse waves must be travelling in opposite directions. Therefore, y₁ and y₂ is the only combination.