Glass prism has refractive index 1.5 and the reflecting angle 90 degree if mere following 18 18 angle of incidence

Understanding Refraction in a Glass Prism
The behavior of light as it passes through a glass prism is governed by the principles of refraction. When a ray of light strikes the prism, its change in direction is determined by the angle of incidence and the refractive index of the material.
Refractive Index
- The refractive index (n) of glass is typically about 1.5.
- This means that light travels 1.5 times slower in glass than in a vacuum.
Angle of Incidence
- When light enters the prism, the angle of incidence (i) is the angle between the incoming ray and the normal (a line perpendicular to the surface at the point of incidence).
- If the angle of incidence exceeds the critical angle, total internal reflection occurs.
90-Degree Reflecting Angle
- With a reflecting angle of 90 degrees, the light ray will reflect off one of the prism's internal surfaces.
- This reflection happens after the ray has refracted as it enters the prism and then strikes the internal surface at the critical angle.
Critical Angle Calculation
- The critical angle (C) can be calculated using the formula:
- C = arcsin(1/n), where n is the refractive index.
- For glass (n = 1.5), the critical angle is approximately 41.8 degrees.
Conclusion
- If a ray of light enters the prism at an angle of incidence greater than 41.8 degrees, it will undergo total internal reflection.
- The light will exit the prism at an angle determined by Snell's law, refracting again as it exits into the air.
Understanding these principles is crucial for analyzing light behavior in optical devices and various applications in physics.