BioMedical Admissions Test (BMAT) 2025 – 400 Free Practice Questions to Pass the Exam

When considering the changes in wave frequency due to various phenomena, it's essential to understand how each phenomenon interacts with the wave.

Reflection is the bouncing back of waves when they hit a barrier. In this process, the frequency of the wave remains unchanged. The reason is that the wave does not lose energy or change its properties; it simply changes direction. Therefore, reflection does not affect the frequency of the wave.

Refraction involves the bending of waves as they pass from one medium to another, which often leads to a change in speed. However, while the speed of the wave changes, its frequency remains constant. This is in accordance with the wave equation, which states that the speed of a wave is the product of its frequency and wavelength. When the speed changes, the wavelength adjusts accordingly to keep the frequency constant.

Diffraction is the spreading of waves when they encounter obstacles or openings. Similar to reflection and refraction, diffraction does not cause a change in frequency, although it can affect the wavelength and direction of the wave.

The option labeled "None" implies that there are no phenomena listed that cause a change in wave frequency. Since all three listed phenomena—reflection, refraction, and diffraction—do not change the frequency, this indicates that the answer