What phenomenon occurs when a wave strikes a boundary at an angle greater than the critical angle?

When a wave strikes a boundary at an angle greater than the critical angle, total internal reflection occurs. This phenomenon is specific to the context of wave behavior, particularly for waves such as light, as they transition from a medium with a higher refractive index to one with a lower refractive index.

At angles greater than the critical angle, the wave cannot enter the second medium; instead, it reflects back entirely into the first medium. This happens because the sine of the angle of incidence exceeds the maximum value allowed by Snell's law, which dictates the relationship between the angles of incidence and refraction based on the refractive indices of the two media involved.

Total internal reflection plays a crucial role in various applications, such as optical fibers, where it allows light signals to be transmitted over long distances with minimal loss. This principle ensures that the light stays within the fiber by reflecting off the boundaries whenever it hits at an angle greater than the critical angle, thereby maintaining signal integrity.

Understanding this concept is essential in wave behavior topics, and it highlights the unique characteristics of wave interactions at boundaries, particularly in the context of optics and light transmission.