Laws Of Reflection
Key Notes :
1. Reflection Defined:
- Reflection is the bouncing back of light when it strikes the surface of an object.
2. Incident Ray:
- The ray of light that strikes a reflecting surface is called the incident ray.
3. Reflected Ray:
- The ray of light that bounces off the reflecting surface is called the reflected ray.
4. Normal Line:
- A line drawn perpendicular (at a 90-degree angle) to the surface at the point where the incident ray strikes it is called the normal line.
5. Angle of Incidence (θi):
- The angle between the incident ray and the normal line is known as the angle of incidence.
6. Angle of Reflection (θr):
- The angle between the reflected ray and the normal line is known as the angle of reflection.
7. First Law of Reflection:
- The incident ray, the reflected ray, and the normal line at the point of incidence all lie in the same plane.
8. Second Law of Reflection:
- The angle of incidence is equal to the angle of reflection (θi = θr).
9. Specular vs. Diffuse Reflection:
- Specular reflection occurs on smooth and shiny surfaces, producing a clear and organized reflection.
- Diffuse reflection occurs on rough surfaces, scattering light in various directions, making it less organized.
10. Examples of Reflection:
Mirrors reflect light in a way that follows the laws of reflection. – Still water surfaces, like ponds or lakes, can also exhibit reflection.
11. Virtual Images:
In a mirror, the reflected rays appear to come from behind the mirror’s surface, creating a virtual image.
12. Application in Everyday Life:
Reflection of light is used in various optical devices, including mirrors, telescopes, and periscopes.
13. Uses in Technology:
Fiber optic cables use multiple reflections to transmit signals over long distances.
14. Safety and Visibility:
Reflectors on bicycles, road signs, and clothing use reflection to enhance visibility at night.
15. Fun Experiments:
Students can perform experiments using mirrors to observe the laws of reflection firsthand.
Let’s practice!
