project report on critical agle and total internal reflection of light in a prism
Answers
Answer:
Whenever a ray of incident light travels from one medium to another, its path is changed i.e. it gets refracted.
If the ray travels from denser medium to rarer medium, it suffers deviation away from the normal at the point of incidence. As the angle of incidence is increased, the angle of refraction also keeps on increasing. At a certain angle of incidence, called the critical angle, the refracted ray grazes along the surface of separation i.e. angle of refraction becomes just go. If the angle of incidence is further increased, no refraction takes place. Instead such a ray gets reflection inside the medium itself. This phenomenon is called total internal reflection.
Explanation:
Total internal reflection is the phenomenon of reflection of light which occurs when a ray of light traveling in a denser medium is incident at the interfere of the two media at an angle greater than the critical angle for that pair of media.
Consider a surface xy separates the rarer medium a from the denser medium b. A ray of light OA from the object O in denser medium incident normally on the surface of separation, gets refracted into the rarer medium as such along AL. Another ray of light incident along the oblique path OA, is refracted away from normal along the path A1B1 in rarer medium. As the angle of incidence is increased, the angle of refraction also goes on increasing, till for a certain angle of incidence C, called the critical angle. When angle of incidence is greater than critical angle then total internal reflection takes place.