Practice question

**Interference of waves** produces enhancement or cancellation based on phase. Two equal amplitude waves out of phase by π cancel completely, A = 0, while in-phase superposition doubles amplitude to 2a, demonstrating energy redistribution without violation of conservation. Maximum constructive interference occurs when the phase difference is zero or a multiple of 2π , aligning crests with crests for maximum amplitude. Using v = fλ and standing-wave condition fₙ = n v/(2L) or v/(4L) as applicable, calculation yields Phase difference of zero, illustrating frequency-length-speed interdependence and quantization by boundaries.