light and EM spectrum

Question 1

what is total internal reflection

Answer 1

when a wave is refracted so much at a boundary that it’s reflected back into a material rather than being transmitted into new material. occurs when a wave travels into a less dense material at an angle of incidence > than the critical angle of the material

Question 2

what is specular reflection

Answer 2

when parallel waves are reflected in single direction by smooth surface

Question 3

what is diffuse reflection

Answer 3

when parallel waves are reflected in lots of directions by rough surface

Question 4

what is a filter

Answer 4

a material that only transmits certain wavelengths of light

Question 5

convex/convergent lens

Answer 5

lens that bulges outwards and causes light rays parallel to axis to converge at principal focus

Question 6

concave/divergent lens

Answer 6

lens that curves inwards and causes light rays parallel to axis to diverge so appear to have come from principal focus

Question 7

what is a real image

Answer 7

an image formed when light rays from a point on an object come together at another point

Question 8

what is a virtual image

Answer 8

an image that is formed when rays appear to have come from 1 point but have actually come from another - light rays don’t actually pass through point

Question 9

what is the Electromagnetic spectrum

Answer 9

continuous spectrum of all possible wavelengths of EM waves

Question 10

intensity meaning & units

Answer 10

power per unit area, W/m^2

Question 11

3 properties when describing images

Answer 11

-magnified/diminished
-upright/inverted
-real/virtual