Reflection of Light

Study Notes

Reflection of Light

Reflection of light occurs when light rays change direction after encountering a surface or other boundary that does not absorb the energy of the radiation.
The type of surface determines how light rays will be reflected differently.

Law of Reflection

States that when light reflects off a plane surface, the angle of incidence will be equal to the angle of reflection.
Illustrated by the diagram showing a ray of light reflecting from a plane surface, with the angle of incidence and angle of reflection measured relative to the normal.
Mathematically represented as: ∠i = ∠r

Types of Reflection

Specular Reflection:
- Occurs on smooth surfaces like mirrors or polished metals.
- Light rays are reflected in the same way, obeying the law of reflection.
- Examples: person's reflection in a mirror, reflection of a mountain on still water, and reflection of light on polished metal surfaces.
Diffuse Reflection:
- Occurs on rough surfaces like gravel or rough water.
- Light rays are reflected at different angles due to surface roughness, causing them to scatter or spread out.
- Examples: reflection of sunlight off sand or gravel, reflection of the moon on rough water, and reflection of lights off paper.

Multiple Reflection

Occurs when there are multiple mirrors with an object between them.
Results in the formation of multiple images, with the number of images dependent on the angle between the mirrors.
Mathematically represented as: n = 360° / θ

Reflection of Light Examples

Responsible for most things people see every day, such as:
- Reflection in a mirror
- Seeing objects outside during the day (reflection of sunlight)
- Seeing the moon at night (reflection of light from the Sun)
Important for vision, as it allows people to see objects that either give off light or reflect light from another source.

Description

Learn about the reflection of light, how it interacts with objects, and how it changes direction after encountering a surface or boundary. Understand the definition and types of reflection based on surface type.