Summary
Light is a form of energy that travels in waves and can move through empty space, unlike sound. It is responsible for phenomena like shadows, reflection, refraction, and dispersion, which help us understand how we see and perceive colors.
- Light — a way of transferring energy that can travel through empty space. Example: Light from the Sun reaches Earth through space.
- Shadow — a dark area where light is blocked by an opaque object. Example: Your shadow on the ground on a sunny day.
- Reflection — the bouncing of light off a surface. Example: Seeing your image in a mirror.
- Refraction — the bending of light as it passes from one medium to another. Example: A straw appearing bent in a glass of water.
- Dispersion — the separation of light into different colors. Example: A prism splitting white light into a spectrum.
- Color — perceived based on the light wavelengths reflected by an object. Example: A red apple reflects red light and absorbs other colors.
Exam Tips
Key Definitions to Remember
- Light is a form of energy that travels in waves.
- Reflection is the bouncing of light off surfaces.
- Refraction is the bending of light when it passes between different media.
- Dispersion is the splitting of light into its component colors.
Common Confusions
- Confusing reflection with refraction.
- Misunderstanding how shadows form.
Typical Exam Questions
- What is the angle of reflection if the angle of incidence is 30°? The angle of reflection is also 30°.
- How does light travel from the Sun to Earth? Light travels in waves through empty space.
- What happens to light when it enters a prism? It is dispersed into a spectrum of colors.
What Examiners Usually Test
- Understanding of how light travels and interacts with different surfaces.
- Ability to explain the formation of shadows and images.
- Knowledge of the laws of reflection and refraction.