Final answer:
Total internal reflection requires light to move from a more to less refractive medium and the incidence angle to exceed the critical angle. This phenomenon is essential in technologies like fiber optics and medical endoscopes.
Step-by-step explanation:
For total internal reflection to occur, two primary conditions must be met. Firstly, the incident light ray must travel from a medium with a higher index of refraction to a medium with a lower index of refraction. Secondly, the angle of incidence in the first medium must exceed the critical angle for that particular pair of media. When these conditions are satisfied, the light ray does not refract into the second medium but is completely reflected back into the first medium. This principle is utilized in technologies such as fiber optics and medical endoscopes, where light travels through fibers of plastic or glass. Additionally, cladding is used to prevent light from escaping the fiber, ensuring that the light is transmitted efficiently through total internal reflection.