Deck 28: Reflection and Refraction

Question 1

A diver shines light up to the surface of a smooth pond at a 10-degree angle to the normal.Some light passes into the air above,and the part that reflects back into the water makes an angle to the normal of

A)less than 10 degrees.
B)10 degrees.
C)more than 10 degrees.

Answer 1

10 degrees.

Question 2

It is difficult to see the roadway in front of you when you are driving on a rainy night mainly because

A)light scatters from raindrops and cuts down the light to reach your eyes.
B)of added condensation on the inner surface of the windshield.
C)the film of water on your windshield provides an additional reflecting surface.
D)the film of water on the roadway makes the road less diffuse.
E)none of these

Answer 2

the film of water on the roadway makes the road less diffuse.

Question 3

A surface that is considered rough for infrared waves may be polished for

A)radio waves.
B)light waves.
C)both of these
D)none of these

Answer 3

radio waves.

Question 4

A yellow-white candle flame reflected from a piece of red glass shows two images;one from each surface.

A)Both images are yellow-white.
B)One image is yellow-white and the other red.
C)Both images are red.
D)Both images are reddish yellow.

Question 5

If you walk towards a mirror at a certain speed,the relative speed between you and your image is

A)half your speed.
B)your speed.
C)twice your speed.
D)none of these

Question 6

The amount of light reflected from the front surface of a common windowpane is about

A)4 percent.
B)8 percent.
C)40 percent.
D)92 percent.
E)96 percent.

Question 7

Standing at the shore of a still lake,the reflected view of scenery on the far side of the lake is the view you would see if you were upside down with your eye in the line of sight

A)where it already is.
B)at the surface of the water where the light reflects.
C)directly beneath you,as far below water level as you are above.
D)close to the distant shore.
E)none of these

Question 8

Diffuse reflection occurs when the size of surface irregularities is

A)small compared to the wavelength of the light used.
B)large compared to the wavelength of the light used.
C)microscopic.

Question 9

When light reflects from a surface,there is a change in its

A)frequency.
B)wavelength.
C)speed.
D)all of these
E)none of these

Question 10

When you look at yourself in a pocket mirror,and then hold the mirror farther away,you see

A)more of yourself.
B)less of yourself.
C)the same amount of yourself.

Question 11

When light passes through an ordinary window pane,its angle of emergence is

A)usually less than its angle of incidence.
B)always less than its angle of incidence.
C)the same as its angle of incidence.
D)usually more than its angle of incidence.
E)always more than its angle of incidence.

Question 12

Light is emitted when

A)electron clouds of atoms are forced into oscillation.
B)atomic nuclei are made to vibrate.
C)electromagnetic waves emanate from matter.
D)high-frequency sound waves strike matter.

Question 13

You wish to photograph the image of your little sister,who is standing 2 meters from a plane mirror.Holding the camera beside her head,you should set the distance for

A)1 meter.
B)2 meters.
C)3 meters.
D)4 meters.
E)none of these

Question 14

The incident light ray,the reflected light ray,and the normal between them

A)lie in the same plane.
B)may or may not lie in the same plane.
C)lie in planes that are perpendicular to one another.

Question 15

Light travels fastest in

A)warm air.
B)cool air.
C)a vacuum.

Question 16

Object and image for a plane mirror lie

A)along the same plane.
B)equal distances from the mirror.
C)at right angles to each other.
D)all of these
E)none of these

Question 17

As a light ray enters or exits a water-air interface at an angle of 15 degrees with the normal,it

A)always bends toward the normal.
B)always bends away from the normal.
C)sometimes bends towards the normal.
D)does not bend.

Question 18

The shortest plane mirror in which you can see your entire image is

A)half your height.
B)about 3/4 your height.
C)about 1/3 your height.
D)equal to your height.
E)dependent on your distance from the mirror.

Question 19

Light will almost always travel from one place to another along a path of least

A)distance.
B)time.
C)effort.
D)expense.
E)complication.

Question 20

To see his full height,a boy that is 1 meter tall needs a mirror that is at least

A)0)33 m tall.
B)0)50 m tall.
C)0)75 m tall.
D)1 m tall.
E)depends on how far the mirror is from the boy

Question 21

A single raindrop illuminated by sunshine disperses

A)a single color.
B)either low-,middle-,or high-frequency colors in most cases.
C)all the colors of the rainbow.

Question 22

Optical fibers are now used by

A)surgeons.
B)mechanics.
C)engineers.
D)all of these

Question 23

When a light beam emerges from water into air,the average light speed

A)increases.
B)decreases.
C)remains the same.

Question 24

The critical angle is least in which of the following?

A)glass
B)water
C)diamond
D)vacuum

Question 25

Your image in a plane mirror is

A)virtual.
B)real.
C)both of these
D)neither of these

Question 26

Refraction causes the bottom of a swimming pool to appear

A)farther down than it actually is.
B)closer to the surface than it actually is.
C)neither.

Question 27

In optical fibers of uniform density,light actually

A)curves in a direction parallel to the central axis of the fiber.
B)travels in straight-line segments.
C)travels along the outer surface of the fiber.
D)None of the above choices are correct.

Question 28

When you view a distant rainbow,each single water drop contributes to the bow

A)a single color.
B)either low-,middle-,or high-frequency colors in most cases.
C)all the colors of the rainbow.

Question 29

The secondary rainbow is dimmer than the primary rainbow because

A)its colors are inverted.
B)it is larger,and its energy is spread over more area.
C)it is farther from the viewer.
D)it simply has much less energy than the primary bow.
E)of an extra reflection and refraction in the drops.

Question 30

The critical angle for a transparent material is the angle at and beyond which all light within the material is

A)refracted.
B)reflected.
C)absorbed.
D)dispersed.
E)diffused.

Question 31

The twinkling of the stars is a result of atmospheric

A)reflection.
B)refraction.
C)scattering.
D)dispersion.
E)aberrations.

Question 32

Light refracts when traveling from air into glass because light

A)has greater intensity in air than in glass.
B)has greater intensity in glass than in air.
C)has greater frequency in air than in glass.
D)has greater frequency in glass than in air.
E)travels slower in glass than in air.

Question 33

The type of lens that spreads parallel light is a

A)converging lens.
B)diverging lens.
C)combination converging-diverging lens.

Question 34

A mirage is a result of atmospheric

A)reflection.
B)refraction.
C)scattering.
D)dispersion.
E)aberrations.

Question 35

Refraction results from differences in light's

A)frequency.
B)incident angles.
C)speed.
D)all of these
E)none of these

Question 36

Atmospheric refraction makes the daylight hours a bit

A)longer.
B)shorter.
C)longer in summer but shorter in winter.

Question 37

At night an underwater scuba diver aims his flashlight beam toward the surface at an angle of 15 degrees with the normal.Upon emerging,the beam angle will be

A)less than 15 degrees.
B)15 degrees.
C)more than 15 degrees.
D)impossible to predict.

Question 38

Rainbows are not usually seen as complete circles because

A)the ground is usually in the way.
B)they are actually elliptical.
C)they have no bottom part.
D)raindrops are not perfectly round.
E)rainbows are actually arched shaped.

Question 39

The average speed of light is greatest in

A)red glass.
B)orange glass.
C)green glass.
D)blue glass.
E)is the same in all of these

Question 40

Different colors are dispersed by a prism because different colors in the prism have different

A)frequencies.
B)speeds.
C)directions.
D)energies.
E)none of these

Question 41

Different colors of light travel at different speeds in a transparent medium.In a vacuum,different colors of light travel at

A)different speeds.
B)the same speed.
C)light travels at the same speed everywhere.

Question 42

If a fish looks upward at 45 degrees with respect to the water's surface,it will see

A)the bottom of the pond.
B)another fish in the pond.
C)the sky and possibly some hills.
D)only the water's surface.
E)none of these

Question 43

A beam of light travels fastest in

A)glass.
B)water.
C)plastic.
D)air.
E)is the same in each of these

Question 44

A person standing waist-deep in a swimming pool appears to have short legs because of light

A)reflection.
B)absorption.
C)interference.
D)diffraction.
E)refraction.

Question 45

Fermat's principle of least time could also be the principle of least distance for the case of

A)reflection.
B)refraction.
C)both of these
D)neither of these

Question 46

Which of the following can be projected onto a viewing screen?

A)a real image
B)a virtual image
C)both
D)neither

Question 47

Rainbows exist because light is

A)reflected.
B)refracted.
C)both of these
D)neither of these

Question 48

The image of the "infinitely-far-away" sun produced by a converging lens appears

A)between the lens and the focal point.
B)at the focal point.
C)beyond the focal point.

Question 49

When a light ray passes at a non-90 degree angle from water into air,it

A)bends toward the normal.
B)bends away from the normal.
C)travels much slower.

Question 50

Fermat's principle of least time applies to

A)reflection.
B)refraction.
C)both of these
D)neither of these

Question 51

When seen from an airplane,a rainbow sometimes forms a complete circle.When this happens,the plane's shadow is

A)in the center of the rainbow.
B)in the lower part of the rainbow.
C)in the upper part of the rainbow.
D)totally outside the rainbow.
E)nowhere,for there is no shadow.

Question 52

Your vision is sharpest when your pupil is

A)dilated.
B)constricted.
C)same either way.

Question 53

Chromatic aberration is a consequence of different colors in a lens having different

A)aberrations.
B)frequencies.
C)energies.
D)critical angles.
E)speeds.

Question 54

A fish outside water will see better if it has goggles that are

A)tinted blue.
B)hemispheres.
C)filled with water.
D)extremely shiny.
E)none of these

Question 55

A "burning glass" used to concentrate sunlight in a tiny spot is a

A)converging lens.
B)diverging lens.
C)either
D)neither

Question 56

When the pinhole in a pinhole camera is made larger,the image is

A)brighter.
B)clearer.
C)both
D)neither

Question 57

Chromatic aberration is absent in

A)converging lenses
B)diverging lenses.
C)front surface plane mirrors.

Question 58

Which of the following are consequences of light's traveling at different speeds in different media?

A)mirages
B)rainbows
C)internal reflection
D)all of these
E)none of these

Question 59

Stars twinkle when seen from the Earth.When seen from the moon,stars

A)twinkle more.
B)twinkle less.
C)don't twinkle.

Question 60

Atmospheric refraction tends to make daytimes

A)longer.
B)shorter.
C)no change in day length

Question 61

As monochromatic light passes from air to glass and back to air,changes are observed in its

A)wavelength,frequency,and speed.
B)wavelength and frequency.
C)wavelength and speed.
D)frequency and speed.
E)None of the above choices are correct.

Question 62

If you wish to hit a blue fish with a red laser beam,you should compensate for refraction between the air and water by aiming your laser

A)directly at the sighted fish.
B)above the sighted fish.
C)below the sighted fish.

Question 63

The moon's redness during a lunar eclipse results from

A)only lower frequencies being reflected from the moon.
B)infrared radiation that is normally blocked.
C)an optical illusion.
D)refraction by the Earth's atmosphere of Earth's sunrises and sunsets.
E)none of these

Question 64

If you wish to spear a fish with a regular spear,you should compensate for refraction between the air and water and throw your spear

A)directly at the sighted fish.
B)above the sighted fish.
C)below the sighted fish.

Question 65

When light is refracted,there is a change in its

A)frequency.
B)wavelength.
C)both of these
D)neither of these

Question 66

The refraction of light in a diamond is greater for

A)long-wavelength light.
B)short-wavelength light.
C)Both refract the same.

Question 67

A mirage occurs for surfaces that are

A)horizontal.
B)vertical.
C)both of these

Question 68

A person who sees more clearly under water without eyeglasses or a face mask is

A)nearsighted.
B)farsighted.
C)neither

Question 69

Ninety percent of light incident on a certain piece of glass passes through it.How much light passes through two pieces of this glass?

A)80%
B)81%
C)85%
D)89%
E)90%

Question 70

When white light goes from air into water,the color that refracts the most is

A)red.
B)orange.
C)green.
D)violet.
E)All refract the same amount.

Question 71

When a pulse of white light is incident on a piece of glass,strictly speaking,the first color to emerge is

A)red.
B)orange.
C)green.
D)violet.
E)They all emerge at the same time.

Question 72

A mirage occurs for road surfaces that are

A)warm.
B)cold.
C)wet.
D)hard.
E)snowy.

Question 73

Use the following figure to answer the question:
From what you know about the refraction of various wavelengths of visible light,would red light and blue light from the same source produce images at the same place?

A)Yes.
B)No.Blue light would make an image closer to the lens.
C)No.Red light would make an image closer to the lens.

Question 74

Magnification from a lens would be greater if light

A)propagated instantaneously.
B)traveled faster in glass than it does.
C)traveled slower in glass than it does.
D)beams spread out more.
E)none of these

Question 75

Use the following figure to answer the question:
The sun's elliptical shape at sunset can be adequately explained by

A)Fermat's principle.
B)the law of refraction.
C)both of these
D)none of these

Question 76

A primary rainbow is brighter than a secondary rainbow because

A)sunlight reaching it is more intense.
B)there is one less reflection inside the water drops.
C)larger drops produce primary rainbows.
D)the secondary bow is a dim reflection of the primary rainbow.
E)none of these

Question 77

Objects infinitely far away are focused by a converging lens

A)in front of the focal point.
B)at the focal point.
C)beyond the focal point.

Question 78

If you wish to hit a red fish with a red laser beam,you should compensate for refraction between the air and water by aiming your laser

A)directly at the sighted fish.
B)above the sighted fish.
C)below the sighted fish.

Question 79

When taking a picture of a nearby object,your camera lens should be moved

A)closer than one focal length from the film.
B)farther than one focal length from the film.
C)to one focal length from the film.

Question 80

If you wish to send a beam of laser light to a space station that is just above the atmosphere near the horizon,you should aim your laser

A)above your line of sight.
B)below your line of sight.
C)along your line of sight.