Light Flashcards
What is an object that gives off its own light?
Luminous Object
Whats an object that doesn’t give off its own light?
Non luminous object
Describe how light travels
In straight lines in all directions at 300,000,000 meters per second
State the Law of Reflection
The angle of reflection is equal to the angle of incidence
Describe the effect that a concave curved mirror has on parallel rays of light
The reflected light rays converge and come to a focal point
Describe the effect that a convex curved mirror has on three parallel light rays
The reflected light rays diverge
What is total internal reflection
Total internal reflection is when light travels through a transparent material such as an optical fibre by reflecting off the inside surface
Provide three examples of uses of fibre optics
Surgical uses such as a Laparoscopy. Transmiting data at 200MPS and can also be used to see hard to reach places such as pipes and sewers.
What happens when light enters a glass block
It refracts towards the normal as it enters the block and away from the normal as it exits the block
What is the Law of refraction?
The angle of refraction is smaller than the angle of incidence when it goes from air into glass
What causes long or short sight?
It is caused by the eyeball being too long or short
If someone’s eyeball is too long where is the image focused?
The image is focused in front of the retina. This means they are short sighted.
If someone’s eyeball is too short, where is the image focused?
The image is focused behind the retina. This means the person is long sighted.
What is the definition of incidence ray?
Its a ray of light that is going to a mirror or surface.
What is the angle of incidence?
The angle of incidence is the angle between the incidence ray and the surface normal.
What’s the reflected ray?
The reflected ray is the ray coming from the mirror or surface
What is the angle of reflection
Its the angle between the reflected ray and the surface normal
What is the surface normal
Its the dotted line at a 90° angle to the surface
What are the colours in the visible light spectrum in order
Red, Orange, Yellow, Green, Blue, Indigo, Violet
Explain Newtons experiment to find the visible colour spectrum
Newton used a prism to disperse the beam of white light into the diffrent colours of the light spectrum.
What are the three primary additive colours
Red, Green and Blue
What colour do you get when you combine red and green
Yellow
What colour do you get when you mix green and blue?
Cyan
What colour do you get when you mix blue and red?
Magenta
