Light Basics
What does rectilinear propagation mean?
Light travels in straight lines.
Does a concave mirror curve inward or outward?
Inward.
What part of the eye controls how much light enters?
Iris
What are the three primary colours of additive colour?
Red, Green, Blue
What type of electromagnetic radiation do we see with our eyes?
Visible Light
What is the difference between a natural and artificial light source?
Natural occurs in nature; artificial is made by humans.
Does a convex mirror provide a wider or narrower field of view?
Wider.
What part of the eye changes shape to focus light?
Lens
Is additive colour based on light or pigments?
Light.
What type of EM radiation is commonly used to see bones?
x-rays
What is the difference between transparent, translucent, and opaque?
Transparent = most light passes through; translucent = some light; opaque = no light.
Which type of lens is thicker in the middle: concave or convex?
Convex.
Put these in order: retina, cornea, pupil, lens.
Cornea → Pupil → Lens → Retina.
What are the three primary colours of subtractive colour?
Cyan, magenta, yellow.
What type of EM radiation can cause sunburn and skin damage?
Ultraviolet (UV) radiation.
What is the difference between fluorescence and phosphorescence?
Fluorescence stops glowing quickly when the energy source is removed; phosphorescence continues glowing.
What happens to light when it passes through a convex lens?
The light rays are refracted and brought together/converged.
What is the retina responsible for?
Detecting light and sending visual information through the optic nerve.
Why does a red object appear red?
It reflects red light into our eyes and absorbs most of the other colours.
How does a microwave oven use electromagnetic radiation?
Microwaves transfer energy to food, causing molecules to move and produce heat.
What is the difference between reflection and refraction?
Reflection is light bouncing off a surface; refraction is light bending/changing direction when it moves between materials.
What type of lens is used to correct myopia?
Concave lens.
How is the human eye similar to a camera?
Both use a lens to focus light and form an image.
What is the difference between myopia and hyperopia?
Myopia makes distant objects blurry; hyperopia makes nearby objects more difficult to see clearly.
Why can radiation therapy be useful in treating cancer?
High-energy radiation can damage the DNA of cancer cells and help destroy them.