EM Spectrum Flashcards
What is refraction?
When a light wave changes speed and direction when passing through a medium
What is reflection?
When a wave bounces off a surface instead of being absorbed or transmitted
When does total internal reflection occur?
When the incident angle is greater than the critical angle
What is the angle of incidence equal to when total internal reflection occurs?
The angle of reflection
What is diffuse reflection?
When reflected light is scattered in all directions from a non-smooth surface
What is specular reflection?
When light is reflected evenly from a smooth surface
What can white light be split up into?
The colours of the visible spectrum
What do filters of light do?
Absorb every other colour apart from the colour it’s meant to be, it transmits this colour through
Why does refraction occur?
Because light waves travel at different speeds in different materials
What happens to the path of the light when it is refracted in glass?
It bends towards the normal when it enters the glass and bends away from the normal when it leaves the glass
When the incident angle is the same as the critical angle is the light reflected or refracted?
It is the largest the incident angle can be for refraction to happen, reflection only occurs when the incident angle is greater than the critical angle
What determines the colour of an object?
The colour of an object depends on which colours the atoms of the object absorb and which one they reflect
What does a converging lens do?
Bends rays of light towards each other, bringing them to a point, helps with long sightedness
What does a diverging lens do?
Bends rays of light away from each other, helps with short sightedness
What determines the focal length of a lens?
How curved the lens is, the more curved it is the shorter the focal length
What does a shorter focal length mean?
The more powerful the lens is
How do lenses bend light?
Using refraction
Are converging or diverging lenses thicker in the middle?
Converging, diverging are thinner in the middle
What does it mean if an object is ‘at infinity’
The distance between a lens and the object is much greater than the focal length of the lens
What is a real image?
An image that can be produced on a screen, the light rays converge and are focused on the screen
What is a virtual image?
An image formed when the object is between the focal point and the lens
What do light rays appear to do in a virtual image?
Diverge but they don’t actually do this
What is the speed of light?
3x10^8m/s
Do all electromagnetic waves travel at the same or different speeds in a vacuum?
The same
