What are the Laws of Reflection of Light?

The laws of reflection describe how light behaves when it strikes and bounces off a reflective surface, such as a mirror. There are two fundamental laws:

First Law of Reflection

• Coplanarity: The incident ray, the reflected ray, and the normal (a line perpendicular to the surface at the point of incidence) all lie in the same plane.

Second Law of Reflection

• Angle Equality: The angle of incidence (the angle between the incident ray and the normal) is equal to the angle of reflection (the angle between the reflected ray and the normal).
  Mathematically: ∠i = ∠r

Special Case

If a ray of light strikes the surface perpendicularly (i.e., along the normal), both the angle of incidence and the angle of reflection are zero, and the ray is reflected back along its original path.

Applications

• Mirrors: The laws apply to flat and curved mirrors, enabling the formation of images.
• Optical Devices: Used in periscopes, telescopes, and other instruments.
• Daily Life: Reflection allows us to see ourselves in mirrors and is fundamental to vision.

Conclusion

The laws of reflection are universal, governing how light interacts with surfaces. Mastery of these laws is essential for understanding optics and designing a wide range of optical devices.