Light and Optics

Question 1

transverse waves that consist of an oscillating electric field and an oscillating magnetic field

Answer 1

electromagnetic waves

Question 2

relative orientation of electric and magnetic fields

Answer 2

perpendicular

Question 3

the range of frequencies and wavelengths found in EM waves

Answer 3

electromagnetic spectrum (RMIVUX G)

Question 4

runs from approximately ____ (red) to ____ (violet)

Answer 4

visible spectrum (700 nm to 400 nm)

Question 5

the rebounding of incident light waves at the boundary of a medium

Answer 5

reflection

Question 6

states that the incident angle will equal the angel of reflection, as measured from the normal

Answer 6

law of reflection

Question 7

line drawn perpendicular to the boundary of a medium

Answer 7

normal line

Question 8

inverted image formed from light that converges at the position of the image

Answer 8

real image

Question 9

upright image formed from light that only appears to be coming from the position of the image but doesn’t actually converge there

Answer 9

virtual image

Question 10

produce virtual, upright images; images are always the same size as the object

Answer 10

plane mirrors

Question 11

have a center, radius of curvature, and a focal point; can produce either virtual, upright images or real, inverted images; can be concave or convex

Answer 11

spherical mirrors

Question 12

distance between center of curvature (c) and the mirror

Answer 12

radius of curvature

Question 13

focal point (ƒ)

Answer 13

ƒ = r / 2

where:
ƒ = focal point
r = radius of curvature

Question 14

converging systems that can produce virtual, upright images or real, inverted images, depending on the placement of the object relative to the focal point

Answer 14

concave mirrors

Question 15

diverging systems that can only produce virtual, upright images

Answer 15

convex mirrors

Question 16

relationship between distances in geometrical optics:

Answer 16

1/ƒ = 1/o + 1/i = 2/r

where:
ƒ = focal length
o = distance between object and mirror
i = distance between image and mirror
r = radius of curvature

Question 17

dimensionless value; ratio of image distance/size to object distance/size; negative value signifies inverted image, positive value signifies upright image

Answer 17

magnification

Question 18

magnification (m)

Answer 18

m = -i/o

where:
m = magnification
i = distance between image and mirror
o = distance between object and mirror

Question 19

ray diagrams for concave mirrors:

object is placed beyond F (focal point)

Answer 19

Question 20

ray diagrams for concave mirrors:

object is placed at F (focal point)

Answer 20

Question 21

ray diagrams for concave mirrors:

object is placed between F (focal point) and the mirror

Answer 21

Question 22

ray diagram for convex mirrors:

Answer 22

Question 23

the bending of light as it passes from one medium to another and changes speed

Answer 23

refraction

Question 24

dimensionless quantity used to describe medium that determines change in the speed of light

Answer 24

index of refraction (n)

Question 25

index of refraction (n)

Answer 25

n = c/v

where:
n = index of refraction
c = speed of light in vacuum (3x10^8 m/s)
v = speed of light in medium

Question 26

speed of light and index of refraction of air

Answer 26

approximately equal to that of a vacuum:
c = 3x10^8 m/s
n = 1

Question 27

states that there is an inverse relationship between the index of refraction and the sine of the angle of refraction (measured from the normal)

Answer 27

Snell’s law (law of refraction)

Question 28

Snell’s law (law of refraction)

Answer 28

n(1) sin θ(1) = n(2) sin θ(2)

where:
n(1) and θ(1) refer to medium light comes from
n(2) and θ(2) refer to medium light enters

Question 29

occurs when light cannot be refracted out of a medium and is instead reflected back inside the medium; happens when light moves from medium with a higher index of refraction to a medium with a lower index of refraction with a high incident angle

Answer 29

total internal reflection

Question 30

minimum incident angle at which total internal reflection occurs; refracted angle θ(2) = 90°; refracted light passes along interface between two media

Answer 30

critical angle (θ(c))

Question 31

when light enters a medium with a higher index of refraction (n(2) > n(1))

Answer 31

light bends toward the normal (θ(2) < θ(1))

Question 32

when light enters a medium with a lower index of refraction (n(2) < n(1))

Answer 32

light bends away from the normal (θ(2) > θ(1))

Question 33

refract light to form images of objects

Answer 33

lenses

Question 34

have focal points on each side

Answer 34

thin symmetrical lenses

Question 35

converging systems that can produce virtual, upright images or real, inverted images

Answer 35

convex lenses ( () )

Question 36

diverging systems that can only produce virtual, upright images

Answer 36

concave lenses ( )( )

Question 37

use required for lenses with non negligible thickness

Answer 37

lensmaker’s equation

Question 38

lensmaker’s equation

Answer 38

P = 1/ƒ = (n-1) (1/r(1) - 1/r(2))

where:
ƒ = focal length
n = index of refraction of lens material
r(1) and r(2) = radius of curvature of first and second lenses

Question 39

used by optometrists to describe lens strength; unit = diopters

Answer 39

power (P)

Question 40

power (P)

Answer 40

P = 1/ƒ

where:
ƒ = focal length

Question 41

addition of multiple lens systems:
focal length-
power-
magnification-

Answer 41

1/f = 1/f(1) + 1/f(2) + 1/f(3) + ... + 1/f(n)
P = P(1) + P(2) + P(3) + ... + P(n)
m = m(1) x m(2) x m(3) x ... x m(n)

Question 42

errors that spherical mirrors and lenses are subject to because of their imperfections

Answer 42

spherical abberations

Question 43

when various wavelengths of light separate form each other; such as the splitting of white light into its component colors using a prism

Answer 43

dispersion

Question 44

a dispersive effect within a spherical lens; light dispersions within the lens leads to the formation of a rainbow halo at the edge of the image

Answer 44

chromatic abberation

Question 45

the bending and spreading out of light waves as they pass through a narrow slit; may produce a large central light fringe surrounded by alternating light and dark fringes with the addition of a lens

Answer 45

diffraction

Question 46

addition of displacements of waves when they interact with each other; supports the wave theory of light

Answer 46

interference

Question 47

shows the constructive and destructive interference of waves that occur as light passes through parallel slits resulting in minima (dark fringes) and maxima (bright fringes) of intensity

Answer 47

Young’s double-slit experiment

Question 48

light in which the electric fields of all the waves are oriented in the same direction; electric field vectors are parallel

Answer 48

plane-polarized light

Question 49

turns unpolarized light passing through it into plane-polarized light

Answer 49

polarizer

Question 50

all of the light rays have electric fields with equal intensity but constantly rotating direction; created by exposing unpolarized light to special pigments

Answer 50

circular polarized light