Light Flashcards
Name 5 Sources of Light
Fire, Stars, Sun, Torches, LEDs.
Name 5 Reflectors of Light
Tinfoil, Silver, Monitors, Glass, Water.
State the Laws of Reflection.
1, The angle of reflection is equal to the angle of incidence.
- The incident ray, the reflected ray, and the normal all lie in the same plane.
Explain how a full water bottle can act as a convex lens to start a fire.
The water bottle can focus using the sun rays and concentrating them, with enough intensity and heat it can start a fire.
What is refraction?
Bending of light as it passes from one medium to another.
State the Laws of Refraction.
- When light enters an optically denser medium the refracted ray will bend towards the normal.
- When light enters an optically less dense medium the refracted ray will bend away from the normal.
Define the following words.
➝ Translucent
➝ Transparent
➝ Opaque
➝ Translucent : Lets some light through.
➝ Transparent : Lets all light through.
➝ Opaque : Lets no light through.
What happens when a beam of light passes through a prism?
The beam of light is split up into the visible spectrum known as ROYGBIV.
How can a magnifying glass be used to start a fire?
A magnifying glass uses a sun ray focused at a point with the rays passing through the lens which can start a fire.
Define these words.
➝ Spectrum of colours.
➝ Dispersion of light.
➝ Spectrum of colors : All the colors.
➝ Dispersion of light : Splitting of light into the visible spectrum.
State the primary colours.
Red, Yellow and Blue.
Why do objects look black?
Because all the colors are being absorbed.
Why do objects look white?
Because all colors are being reflected.
Why do objects look green?
Because every color is being absorbed except green which is instead reflected.
A beam of red light is mixed with a beam of green light what color is produced?
Yellow.
