The angle of incidence always which of the following?

The angle of incidence always which of the following?

• A. Equals the Angle of Refraction
• B. Is Independent of Surface
• C. Equals the Angle of Reflection
• D. Is Double the Angle of Reflection

Answer: (C)

The angle of incidence always equals the angle of reflection. This comes from the law of reflection, which says that for a smooth, mirror-like surface the incoming ray, the reflected ray, and the normal to the surface all lie in the same plane, and the angle between the incoming ray and the normal is equal to the angle between the reflected ray and the normal. This equality holds regardless of the specific surface, as long as the reflection is specular (not diffuse). It’s different from refraction, where the angle of the ray changes when crossing into a different medium according to Snell’s law; that change depends on the refractive indices, not on the surface itself. The other options aren’t general truths: the incidence angle isn’t about the surface being irrelevant, it isn’t typically equal to the refracted angle, and it isn’t simply double the reflected angle.

The angle of incidence always equals the angle of reflection. This comes from the law of reflection, which says that for a smooth, mirror-like surface the incoming ray, the reflected ray, and the normal to the surface all lie in the same plane, and the angle between the incoming ray and the normal is equal to the angle between the reflected ray and the normal. This equality holds regardless of the specific surface, as long as the reflection is specular (not diffuse). It’s different from refraction, where the angle of the ray changes when crossing into a different medium according to Snell’s law; that change depends on the refractive indices, not on the surface itself. The other options aren’t general truths: the incidence angle isn’t about the surface being irrelevant, it isn’t typically equal to the refracted angle, and it isn’t simply double the reflected angle.