Download Introduction to Light and Optics

Date:
Name:
What is Light?
1. What is light?
Light is a form of energy visible to the naked eye
It is an electromagnetic wave
2. Three properties of light are:
i)
It travels in straight lines
ii) It does not need a medium to travel through
iii) Travels very fast
What is the value of c?
c = speed of light = 3.00 X 108 m/s
300 000 000 m/s
3. a) What is the electromagnetic (EM) spectrum?
It is a range of radiant energy that travels as an electromagnetic wave
b) Study the chart below showing the various forms of EM radiation.
energy
low
wavelength
long
high
short
frequency
low
1
2
3
4
Cycles per second
c) Describe the visible spectrum
ROYGBIV
4. What are some uses for the following electromagnetic waves?
Type of
Uses
Electromagnetic Wave
Radio Wave
AM / FM Radio
Radar
TV signal
Astronomy
Cell phones
Microwave
Telecommunications
Cooking
Astronomy
Infrared Light
Remotes
Food warming
Lasers
Physio
heat detection
high
5
Visible Light
Ultraviolet Light
X-Rays
Gamma Rays
Human vision
Stage lighting
Rainbows
Sunburn
increases risk of skin cancer
Makes vitamin D in skin sterilizes water (kills bacteria)
Black lights
Medical imaging
Security
Cancer treatment
Cancer treatment
Produced in nuclear reactions
5. a) Define luminous and provide an example.
Capable of Producing its own light
e.g.
Sun, candle, light bulb
b) What is a non-luminous object? How can we see a non-luminous object?
Does not produce its own light but reflects some frequencies of light
that are captured by our eye (retina)
6. Describe the difference between transparent, translucent and opaque materials. Give examples.
Transparent:
Glass, Kool aid, coloured glass
Light can pass through (you can read writing
through it)
Translucent:
Grease spot on a paper bag
Light can pass through but you cannot read
writing through it
Opaque:
Light cannot pass through
Curtains, walls, tree etc.