Question

Reflected waves change their wavelength by ______ when reflected.

A. ¾
B. ½
C. They don’t change
D. ¼

Answer 1

Reflected waves maintain their wavelength upon reflection, but may undergo a 180° phase change, equivalent to a path length change of λ/2.

Step-by-step explanation:

Reflected waves do not change their wavelength simply due to reflection; instead they may undergo a change in phase. Specifically, when light reflects from a medium with a higher index of refraction than the medium it is traveling in, a 180° phase change occurs. This phase shift is equivalent to a change in path length of λ/2, where λ is the wavelength of the wave. However, the actual wavelength of the light remains unchanged during the reflection process.