ch. 18

Question 1

when you look at an object in the mirror, the image is

Answer 1

behind the mirror

Question 2

When an object like a tree is illuminated by the sun, and you are looking toward the tree, light rays leave the object

Answer 2

from every point on the surface of the tree, and in every direction

Question 3

Part complete
A ray of light impinges on a transparent material at some angle with the normal. If the material has a higher index of refraction, as it enters, the ray will ______________.

Answer 3

bend to make a smaller angle with the normal

Question 4

What conditions are necessary for total internal reflection to occur?

Answer 4

angle 1 must be greater than the critical angle and n2<n1

Question 5

what does angle of refracted light depend on

Answer 5

it depends on the indexes of refraction of the materials and the angle of the incident ray

Question 6

When light hits the boundary between two different materials, it can undergo

Answer 6

both reflection and refraction

Question 7

When viewing an object that is immersed in water, the image that is formed is __________.

Answer 7

a virtual image

Question 8

The focal length of a converging lens is __________.

Answer 8

the distance at which parallel light rays are focused.

Question 9

What does a negative magnification indicate?

Answer 9

inverted and real

Question 10

The shape of a diverging lens is ______________.

Answer 10

thinner in the center than around the edges

Question 11

The shape of a converging lens is ______________.

Answer 11

thicker in the center

Question 12

if a lense creates a real image? is it converging or diverging

Answer 12

diverging lenses only make virtual images, converging can make ether

Question 13

what is an extended source

Answer 13

it is a source where every point acts as a point source

Question 14

what is a point source

Answer 14

it is a source of idealized light that emis rays in all directions

Question 15

when will a point source or extended source be seen

Answer 15

they will be seen always, they have rays that emit from all directions and can be seen from all angles

Question 16

when a ray is at an interface, what can happen

Answer 16

it can be reflected or refracted

Question 17

when a light is in a material, what can happen

Answer 17

it can be scattered or absorbed

Question 18

what is scattering

Answer 18

single rays are broken into weaker rays that point in all directions

Question 19

when an object intercepts a point source, what happens

Answer 19

a sharp shadow is created

Question 20

when a object blocks a extended source, what happens

Answer 20

there is a large collection of point sources that each produce their own shadow so the shadow is blurry and overlapped

Question 21

what is the law of reflection

Answer 21

it states that the angle to the normal that the incident light makes, is the same angle that the angle of reflection makes with the normal

Question 22

what are diffuse surfaces

Answer 22

they are surfaces that are rough and create reflected rays that point in many directions and do not produce an image

Question 23

in a plane mirror, where do the rays come from? where do they appear to come from?

Answer 23

they come from object P, but appear to come from P’

Question 24

what is a virtual image generally

Answer 24

it is the point where the reflected rays APPEAR to diverge from, but no actual light comes from this point

Question 25

in a plane mirror, the image distance s' is _____ to the object distance s

Answer 25

equal to

Question 26

what is a virtual image

Answer 26

it is an upright image that appears to be the source of ray divergence

Question 27

what is refraction

Answer 27

it is when light continues into a second medium but it bends or changes direction

Question 28

when the incident light passes into a material with a larger index of refraction, what happens to the refracted ray

Answer 28

the angle gets closer to the normal

Question 29

when incident light passes into a material with a smaller index of refraction, what happens to the refracted ray

Answer 29

it moves away from the normal

Question 30

when does total internal reflection occur

Answer 30

when n2

Question 31

when is there no total internal reflection

Answer 31

when n2> n1

Question 32

A diverging mirror produces what kind of images?

Answer 32

only virtual images

Question 33

what is a converging lens

Answer 33

it is a rounded lens that causes rays to refract toward the optical axis

Question 34

for a converging lens, all rays that point initially parallel to the optical axis converge at the _______

Answer 34

focal point

Question 35

what is the distance of the focal point from the lens called

Answer 35

the focal length

Question 36

what is the near focal point

Answer 36

it is the point on which the light is incident

Question 37

what is the far focal point

Answer 37

opposite side of near

Question 38

for a converging lens, initially parallel rays will

Answer 38

refract through the focal point on the far side

Question 39

for a converging lens, a ray initially passing through the focal point will

Answer 39

emerge parallel

Question 40

for a converging lens, a ray initially passing through the center in a straight line will

Answer 40

continue in a straight line

Question 41

A converging lens with an object outside the focal length (s>f) will create what type of image

Answer 41

an inverted real image

Question 42

what are real images

Answer 42

points where the rays appear to converge

Question 43

when the magnification is negative

Answer 43

the image is inverted, real

Question 44

when the magnification is positive

Answer 44

the image is upright, virtual

Question 45

what does it mean if s' is negative

Answer 45

it means the image is on the same side as the object

Question 46

for a converging lens, if an image is on the same side as the object what type of image is it, what is true of s'?

Answer 46

it is virtual, s' is negative

Question 47

what is the shape of a diverging lens

Answer 47

it is thinner at its center

Question 48

where is the focal length for converging lenses

Answer 48

it is the distance from the lens to the point where parallel rays converge to

Question 49

where is the focal length for a diverging lense

Answer 49

it is the distance from the lens to the point where the parallel rays appear to diverge from

Question 50

for a diverging lens, what happens to parallel rays

Answer 50

they defract outwards and appear to diverge from the near focal point

Question 51

for a diverging lens, rays that are directed toward the far focal point will

Answer 51

emerge parallel

Question 52

for a diverging lens, rays directed at the center of the lens will

Answer 52

emerge through in a straight line

Question 53

what types of images do diverging lenses make

Answer 53

they only make virtual images

Question 54

what is a converging mirror

Answer 54

the parallel rays reflect and appear to converge to a point

Question 55

what is a diverging mirror

Answer 55

parallel rays appear to diverge from the focal point behind the mirror