Wave Interference Explained | Physics Question

Physics Question on Wave Interference

Question:

When two identical waves of the same wavelength (λ) and amplitude (A) interfere in phase, what is the amplitude of the resulting wave?

    Options:

    A. A

    B. 3A

    C. 4A

    D. 2A

When two waves with the same amplitude (A), same wavelength (λ), and same phase meet, they undergo constructive interference.

This means their displacements at every point add together to form a new wave with a larger amplitude.

Mathematically, if each wave is represented as:

y₁ = A sin(kx)

and

y₂ = A sin(kx)

Then, the combined wave (resultant) is:

y = y₁ + y₂ = A sin(kx) + A sin(kx) = 2A sin(kx)

Therefore, the resulting wave has an amplitude of 2A.

Answer: D. 2A