Question

multiple-choice question
when a wave hits a fixed boundary, it is
refracted and inverted.
reflected and inverted.
reflected.

Explanation:

To solve this, we recall wave behavior at boundaries. A fixed boundary (like a string tied to a wall) causes the wave to reflect. When reflecting off a fixed boundary, the wave is also inverted (phase change of 180° or π radians). Refraction involves a change in medium (not just a boundary reflection), so the first option is wrong. The third option is incomplete as it doesn't mention inversion. So the correct description is reflection with inversion.

Answer:

B. reflected and inverted. (assuming the options are labeled as A: refracted and inverted, B: reflected and inverted, C: reflected)