CH 6 Refraction of Light | Standard 10th Science & Technology Part 1 | English Medium

1위@jeffjo87323 hours ago

Neither "Partial Internal Reflection" nor "Internal Reflection" a defined concept in optics. Both are just descriptions with no significant consequences. In particular, you use "Partial" for when the reflection is not TIR. But there is one case where the reflection is 100% but is not classified as TIR. The Fresnel Equations define the coefficients of reflection and transmission, which need to be in the range [0,1]. When going from a rare to a dense medium, the Fresnel equations satisfy this. When going from a dense to a rare medium, the Fresnel equations can't be solved if the angle of incidence is greater than the critical angle. This is called "Total Internal Reflection" because the Fresnel Equations are ignored. The coefficient of reflection is set to exactly 1. But at the critical angle, the Fresnel Equations can be solved, and says that the coefficient of reflection is 1. This has nothing to do with the reflection occurring "inside" or "outside" an object; in fact, reflection depends exclusively on the angle a ray makes with the surface at a single point. I don't even know why the word "internal" is used in the name. The only thing it seems to accomplish, it to suggest the wrong explanation you give for rainbows. TIR is impossible in spherical raindrops. The angle of incidence for the internal reflection is equal to the angle of refraction as the ray entered the drop. Which, by definition, must be less than the critical angle. The dispersion caused by refraction is also not directly the cause. Each color of light exist the drop at all angles to 0 to its "rainbow angle," but is much brighter in the outer half-degree of this range. Dispersion in this case says that the rainbow angle varies with color.번역 보기