WEEK 7 - Topic 17 - Light and Optics (Overview) Flashcards
What is the wavelength range of visible light?
400-700 nm
Which part of the electromagnetic spectrum do human eyes respond to?
Visible light
What does electromagnetic radiation include? List them from longest wavelength to shortest
All energy waves
- Radio
- Microwave
- Infrared
- Visible
- UV
- X-ray
- Gamma
What does different wavelengths of the visible spectrum reflect?
Different wavelengths = different colours of the visible spectrum
(REVISION) What is frequency?
Number of cycles (of waves) per unit time
What is refraction?
Bending of light
What happens when light travels from one medium into a less dense medium?
Speeds up
What happens when light travels from one medium into a more dense medium?
Slows down
Why does light refract when travelling from one transparent medium into another with a different density?
Light ray refracts because the speed of the light changes as it hits the surface of the different medium at an oblique angle.
What happens to light when it hits a convex lens?
The light rays bend so that they converge at a focal point.
The more convex a lens is, the…?
- more the light bends; and
- the shorter the focal distance.
What is the focal distance?
Distance between lens and focal point
What is a real image?
The image formed by a convex lens.
What happens to the real image?
It is inverted; upside down and reversed from left to right.
What do concave lenses do to light?
Concave lenses
- diverge light
- prevent light from focusing
- extend the focal distance
