What is a characteristic application of Snell's law?

• A. Calculating fluid flow through a pipe
• B. Determining angle changes when light passes through different materials
• C. Measuring the change in sound frequency due to motion
• D. Assessing air pressure variations

Answer: (B)

Snell's law, also known as the law of refraction, specifically describes how light travels through different media and how its direction changes when it does so. When light passes from one material to another—such as from air into water or glass—the speed of light changes, which causes the light ray to bend at a specific angle. The relationship between the angles of incidence and refraction, as well as the refractive indices of the two materials, is given by Snell's law. This fundamental principle is extensively applied in optics to design lenses, analyze optical systems, and understand various phenomena involving light.

In contrast, calculating fluid flow through a pipe focuses on fluid dynamics rather than light, measuring sound frequency changes relates to the Doppler effect in wave phenomena, and assessing air pressure variations pertains to fluid statics and atmospheric science. These applications do not directly involve the concepts of refraction or the relationship between angles and refractive indices that define Snell's law.