What happens to the frequency of a sound wave when it passes from air into water?

💡 Solution & Explanation

The frequency of a wave is determined entirely by the vibrating source and remains constant when the wave crosses the boundary into a new medium, whereas speed and wavelength change proportionally according to the refractive index. Incorrect options incorrectly suggest that wave frequency alters with medium density or drops to zero upon refraction. The color of light, which depends on its frequency, does not change when it enters water from air.