Principles of Light
What is light?
A form of energy
What part of the electromagnetic spectrum can we see?
Visible light
What is the law of reflection?
Angle of incidence = angle of reflection
What is refraction?
The bending of light when it passes between materials
What part of the eye focuses light?
Lens
How does light travel?
In straight lines (rays)
Which EM waves have the longest wavelength?
Radio waves
What is the “normal line”?
An imaginary line perpendicular to a surface
What causes light to bend?
Change in speed due to different density
What does the retina do?
Detects light and sends signals to the brain
What happens when light hits an opaque object?
It doesn’t pass through—it's absorbed or reflected
Which EM waves have the most energy?
Gamma rays
What kind of image does a plane mirror make?
Same size, upright, reversed
What does a convex lens do?
Focuses (converges) light to a point
What’s the difference between nearsightedness and farsightedness?
Nearsighted = can see close; Farsighted = can see far
What does translucent mean?
Some light passes through, but it's scattered
How are wavelength and energy related?
Shorter wavelength = more energy
What does a concave mirror do to light?
Converges (focuses) the light
What does a concave lens do?
Spreads out (diverges) light rays
What type of lens corrects nearsightedness?
Concave
Why does light behave differently with different objects?
Because of how the material interacts with the rays (absorb, reflect, transmit)
Name three types of EM waves besides visible light.
X-rays, UV rays, microwaves, infrared, radio, etc.
Name a use for a convex mirror.
Security mirror, vehicle side mirror (wide field of view)
Why do objects look bent in water?
Light refracts as it enters or leaves the water at an angle
What do cones in your eye help you see?
Colour