Reflection

Summary

Reflection occurs when light bounces off a surface, creating an image that is the same size and distance as the object. The image is virtual and cannot be projected onto a screen.

• Reflection — the bouncing back of light from a surface. Example: Seeing your face in a mirror.
• Virtual Image — an image formed by rays that appear to converge but do not actually meet. Example: The image seen in a plane mirror.
• Specular Reflection — reflection from a smooth surface in a single direction. Example: Light reflecting off a mirror.
• Diffuse Reflection — reflection from a rough surface causing scattering. Example: Light reflecting off a wall.
• Law of Reflection — the angle of incidence is equal to the angle of reflection. Example: A light ray hitting a mirror at 30° will reflect at 30°.

Exam Tips

Key Definitions to Remember

• Reflection: The bouncing back of light from a surface.
• Virtual Image: An image formed by rays that appear to converge.
• Specular Reflection: Reflection from a smooth surface in a single direction.
• Diffuse Reflection: Reflection from a rough surface causing scattering.
• Law of Reflection: The angle of incidence equals the angle of reflection.

Common Confusions

• Thinking a virtual image can be projected onto a screen.
• Confusing specular and diffuse reflection.

Typical Exam Questions

• What is the angle of reflection if a light ray hits a mirror at 30°? The angle of reflection is 30°.
• How does a virtual image differ from a real image? A virtual image cannot be projected onto a screen.
• What happens to light when it hits a rough surface? It undergoes diffuse reflection and scatters in many directions.

What Examiners Usually Test

• Understanding of the law of reflection.
• Ability to distinguish between specular and diffuse reflection.
• Drawing and interpreting ray diagrams for reflection.