Light

Front 1

refraction

Back 1

- bending of light through different transparent media

- fast in gas > liquid > solid

Front 2

when light travels from denser medium to less dense medium

Back 2

- speed increases

- ray bends away from normal

Front 3

when light travels from less dense medium to denser medium

Back 3

- speed decreases

- ray bends towards normal

Front 4

Back 4

incident ray does not touch boundary

refracted ray does not touch boundary

Front 5

refractive index

Back 5

- no units

- n > 1

- RI increase = SOL decrease

n = vacuum/air ÷ medium

Front 6

snell's law

Back 6

n1sin@1=n2sin@2

light follows same path if reverse

used to find angle of incidence/refraction

Front 7

critical angle

Back 7

angle of incidence such that angle of refraction is 90

use to determine total internal reflection

Front 8

total internal reflection

Back 8

- complete reflection of a light ray inside an optically denser medium at its boundary with an optically less dense medium

- light ray must travel from a denser medium to a less dense medium

- i > c

Front 9

lenses

Back 9

parallel light rays converge/diverge after passing through lenses due to refraction

Front 10

principal axis

Back 10

horizontal line passing through optical lens center

Front 11

optical center

Back 11

midpoint between surfaces on lens on its principal axis (not where light ray is refracted)

Front 12

focal point

Back 12

point at which all light rays parallel to the principal axis converge after refraction by the lens

behind optical center

Front 13

focal length

Back 13

distance between optical center to focal point

Front 14

ray diagrams

Back 14

rays always follow one of 3 characteristics:

1) passes through the optical center

2) is parallel to principal axis then refracts to pass through the focal point after the optical center

3) passes through the focal point before the optical center then is parallel to principal axis

Front 15

object >2F

Back 15

image is inverted, real, diminished

eg: camera & eye

Front 16

object = 2F

Back 16

image is inverted, real, same size

eg: photocopier

Front 17

F < object < 2F

Back 17

image is inverted, real, magnified

eg: projector, photograph enlarger

Front 18

object = F

Back 18

image is upright, virtual, magnified

eg: spotlight (producing parallel beam of light)

Front 19

object < F

Back 19

image formed is upright, virtual, magnified

eg: magnifying glass

Front 20

Back 20

object > 2F : diminished, real

object @ 2F : same size

F < object < 2F : magnified, real

object @ F : //

object < F : virtual, magnified