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59 Cards in this Set
- Front
- Back
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What is light? |
A form of radiant energy visible to the human eye. |
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What does radiate mean? |
To "move out in all directions" |
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What form of energy is radiant energy? |
Kinetic energy. |
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What does transparent mean? |
All light is transmitted through it. |
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What does translucent mean? |
Some lift is transmitted through while some is absorbed or reflected. |
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What does opaque mean? |
All light is either absorbed or reflected. |
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What are the four properties of light? |
1. Light travels in straight lines called rays. 2. Light travels very fast (3.0 x 108 m/s). 3. Transfers energy by radiation does not require a medium. 4. Light is an electromagnetic wave. |
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What is the relationship between wavelength and frequency? |
As a wavelength increases, the frequency decreases. |
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What is the wavelength and frequency like when a light Ray carries a lot of energy? |
Small wavelength, increasing frequency. |
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What are the different types of light rays? |
Gamma rays, X-Rays, Ultra violet, Visible light, infra red, microwaves/radar, and TV/radio. |
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What is the application of Gamma rays? |
Sterilization. Cancer treatment. Pasteurizing milk. |
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What is the application of X-rays? |
Radiography. Cancer treatment. Airport security. |
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What is the application of ultra violet light? |
Criminology->some stains. Security markings. Detection and destruction of bacteria. |
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What is the application of visible light? |
What allows us to see and detect colour. |
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What is the application of Infra red? |
Night time surveillance. Laser surgery. Weather forecasting. Remotes. Heat sealing missiles. |
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What is the application of microwaves/radar? |
Radar in weather forecasting. |
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What is the application of TV and radio rays? |
TV and radio. |
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What are different sources of light? |
Incandescence, fluorescence, compact fluorescent light bulbs (CFL), Light Emitting Diode (LED), phosphorescence, electric discharge, chemiluminescence, bioluminescence, and triboluminescence. |
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Describe incandescence. |
The production of light due to high temperature. |
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Describe fluorescence. |
The emission of light by a substance that has absorbed light/other electromagnetic radiation of a different wavelength. |
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Describe compact fluorescent light bulbs. |
A type of fluorescent light which can fit into most existing light fixtures. Is cooler, more energy efficient, and lasts longer. |
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Describe light emitting diodes. |
Emit light when an electric current flows one way through a semi conductor. |
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Describe phosphorescence. |
A photo luminescent material "glows" after the radiation causing it to "glow" has ceased. |
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Describe electric discharge. |
The process of emitting light because of electricity passing through a gas. |
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Describe Chemiluminescence. |
The process of light emitting light energy when two or more chemicals mix together and react chemically. |
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Describe bioluminescence. |
What chemiluminescence occurs in living things. |
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Describe triboluminescence. |
Light generated when material is pulled apart, ripped, scratched, crushed, or rubbed through the breaking of chemical bonds. |
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What is a mirror? |
Any polished surface that reflects light. |
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What are the two laws of reflection? |
1. The angle of incidence equals the angle of reflection. 2. The incident ray, the reflected ray, and the normal all lie on the same plane, in front of the mirror. |
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What is diffused reflection? |
Light is reflected off irregular surfaces illuminating what is around it. |
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What does SALT stand for? |
Size. Attitude. Location. Type. |
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Use of convex mirrors: |
Door mirror of a car. In shops to detect shoplifters. At concealed entrances to give a view of oncoming traffic. |
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Use of concave mirrors: |
Search lights. Flood lights. Headlights in a car. Makeup mirrors. |
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Where does the light ray move if the light is traveling from a less dense medium to s more dense medium? |
Toward the normal. |
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Where does the light Ray move if the light ray is traveling from a more dense medium to a less dense medium? |
Away from the normal. |
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What is optical density? |
The speed of light in a medium. |
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How do you calculate the index of refraction? |
N=C/V V=C/N N=NxV
N-index of refraction. C-speed of light in a vacuum. V-speed of light in given medium. |
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How do you calculate the index of refraction travelling from air? |
N=sin0i/sin0r
0i-incident light Ray through air. 0r-refracted light Ray through other medium. |
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Calculate the index of refraction in the first medium. |
N1=sin01/sin02 |
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Calculate the index of refraction on the second medium. |
N2=N1sin01/Sin02 |
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Calculate the angle of incidence. |
Sin01=N2sin02/N2 |
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Calculate the angle of refraction. |
Sin02=N1sin01/N2 |
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When does total internal reflection occur? |
-When light is travelling more slowly in the 1st medium than in the 2nd. -The angle of incidence is big enough that no refraction occurs into the 2nd medium. -The larger the index of refraction, the smaller the critical angle. |
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How do you calculate critical angle? |
0c=sin-1(nR/n1) |
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What is a lens? |
Any transparent object having two or more non-parallel curved surfaces, or one plane surface and one curved surface. |
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Where are converging lenses thicker? |
In the middle. |
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Where are diverging lenses thicker? |
At the edges. |
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Calculate magnification using the height of the objects. |
M=hi/ho |
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Thin lens equation. |
1/F=1/di+1/do |
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What is hyperopia. |
Far-sightedness. |
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What does it mean to be far-sighted? |
You can see far away. |
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Where does the light focus if you are far-sighted? |
Behind the retina. |
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What is presbyopia? |
Far-sightedness you get when you age. |
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What is myopia? |
Near-sightedness. |
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What does it mean to be near-sighted? |
You can see near. |
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Where does the light focus of you are near-sighted? |
In front of the retina. |
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How do you fix hyperopia? |
Using a positives miscues. Using a converging lens. |
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How do you fix myopia? |
With a negative meniscus. Using a diverging lens. |
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What are the different parts of the eye? |
Iris. Pupil. Cornea. Lens. Optic nerve. Retina. |
