When a wave is reflected from a rigid boundary (fixed end of a string)…

Question

When a wave is reflected from a rigid boundary (fixed end of a string), the reflected wave undergoes

Accepted Answer

D. {'text': 'A phase change of π (180°)', 'label': 'D'}

1. At a fixed (rigid) end, boundary condition requires zero displacement.
2. The reflected wave must cancel the incident at that point.
3. This forces a phase change of π on reflection from a rigid boundary.
4. At a free end (open string end), the reflection has NO phase change.
_Source: NCERT Class 11 Physics, Ch 14 "Waves", §14.6_

Answer

{'text': 'No phase change', 'label': 'A'}

Answer

{'text': 'Amplitude doubling', 'label': 'B'}

Answer

{'text': 'A phase change of π/2 (90°)', 'label': 'C'}