physics iclickers ii

what is light

an electromagnetic wave

diffuse reflection

occurs when light strikes a surface that os not smooth and polished but rough

you are standing on the right side of a closed opaque box. there is a hole and all surfaces are painted black. if there is a hole behind a wall and you look through the holes, what can you see?

the black walls of the box. diffuse reflection.

you are talking to a friend in a closed room with no windows objects or furniture, only an incandescent light. does reflection play s room in seeing your friend?

yes, visible light from the overhead bulb is diffusely reflected from my friend and enters my eye

when light passes from air to water it bends

towards the normal and slows down

critical angle

angle of incidence that produces a refracted ray at 90°

refraction of light at the air water interface means that

fish and other objects in the water are closer to the surface (shallower) than they appear

dispersion

the amount of refraction, change in direction, varies with wavelength

white light is incident on a prism. after it passes through the first, a color spectrum is observed. as it passes through the second, what color exits

is white in color

does the speed of light in glass depend on its wavelength

yes

rainbow

separation of colors when sunlight refracts into and out of falling raindrops

angle that the rainbow appears from antisolar point

42

second rainbow

double internal reflection as opposed to single internal reflection

bottom of spoon

convex, virtual

inside of spoon

concave, real

where must an object be placed in front of a converging lens on order to obtain a virtual image

between focal point and lens

an ordinary magnifying glass in front of an erect object produces an image that is

virtual and erect

3 cases for reflection from spherical surface

convex, concave outside focal point, concave inside focal point

real image

camera lens

virtual image

magnifying glass

a virtual image is one...

from which light rays diverge but do not pass through

the term virtual as applied to an image made by a mirror or lens means that the image

cannot be shown directly on a screen

concave mirror real image

outside focal point, inverted

concave mirror virtual image

inside focal point, upright

convex mirror

ONLY VIRTUAL AND UPRIGHT

an object is placed at the center of curvature of a concave spherical mirror. which describes the image

inverted same size real

all images formed by convex mirror are upright and virtual

true

for a concave mirror all inverted images are

real

for a concave mirror all upright images are

virtual

which of these 5 cases is the image a real image

A and C, no dotted lines that connect to the tip of the image

s>f

real image

s<f

virtual image

diverging

convex

converging

convex

a converging lens and a screen are so arranged that an image of the sun falls on the screen, the distance from the lens to the screen is

the focal length

an object is 30 cm in front of a converging lens of focal length 10 cm. the image is

real and smaller than the object

a small object is 15 cm to the left of a converging lens that has a focal length of 15 cm. a second converging lens that also has a focal length 15 cm is located 20 cm to the right of the first lens. light from the object passes through the first lens and

continues to the right without forming an image

a small object is 15 cm to the left of a converging lens that has a focal length of 15 cm. a second converging lens that also has a focal length 15 cm is located 20 cm to the right of the first lens. the final image formed by the second lens is

20 cm to the right of the second aka at the focal point of the second

a small object is 15 cm to the left of a converging lens that has a focal length of 15 cm. a second converging lens that also has a focal length 15 cm is located 20 cm to the right of the first lens. the final image position is

real inverted same size as object

the rainbow seen after a rain shower is caused by

refraction

coherent

same phase, waving up and down in unison

constructive interference

one path is a whole wavelength longer than the other, waves start and arrive in phase

destructive interference

one path is half a wavelength longer than the other, waves start in phase but arrive out of phase

fringe spacing

how far apart the bright spots are

which of the following statements about young's double slit experiment is false

the results support the particle theory of light

diffraction

waves go around corners

double slit

interference + diffraction

in an experiment to demonstrate interference of light, it is essential that

coherent sources of light be used

two wavelengths, 650 and 430, are used in a single slit experiment. the graph shows intensity versus angle for the diffraction patterns. if both are used simultaneously, what color will be seen in the combined pattern at A and B?

A; 650 B; 430

diffraction occurs when light passes

by a small particle

through a small hole

through a double slit

by a sharp edge

it occurs in all of these conditions

two waves shown come from a source where they were initially coherent. the path difference could be

1/4 wavelength

a wave front is a surface of constant

phase

interference of light is evidence that

light is wave phenomenon

the reason there are two slits rather than one in young's experiment is

to create a path length difference

as the width of the slit producing a single slit diffraction patterns is slowly and steadily reduced, the diffraction pattern

slowly and steadily gets wider

waves from two slits are in phase at the slits and travel to a distant screen to produce the second minimum of the interference pattern. the difference in the distance traveled by the wave is

3 halves of a wavelength

in an experiment to measure the wavelength of light using a double slit, it is found that the fringes are too close together to easily count then. the spread them out,

reduce the slit separation by half

if 2 light waves are coherent

their phase differences are constant

if light traveling in 1 medium strikes the surface of a second medium in which light travels ore slowly

there is a phase change of pi in the reflected light

a phase shift of 180° occurs when a light wave

reflects form the boundary surface of a medium that is more dense than the medium in which the wave is traveling

an electric field in unpolarized light

can be in any direction perpendicular to the direction of propagation

the image formed by a normal flat mirror is

virtual

which of the following is true of all virtual images

seen but not photographed

appear only briefly

smaller than the objects

larger than the objects

none

none of the above

2 parallel beams of monochromatic light in the air are incident on a plane of glass surface. in the glass the beams

remain parallel

real images formed by a spherical mirror are always

on the same side of the mirror as the object but closer to the mirror than the object

an erect object is in front of a convex mirror a distance greater than the focal length. the image is

virtual, erect, smaller than the object

in a youngs double slit experiment it is essential that two beams

come originally from the same source

focal length

distance from lens to focal point

a beam of polarized light is coherent

false

in a media denser than air, water or glass, the speed of kight is different for different colors

true

radio waves are the same thing as x rays just longer wavelength and lower frequency

true

a polarizing filter passes light with magnetic field vectors aligned parallel to the axis of the filter

true

e-m radiation consists of altering e and m fields where 1 is wt max intensity and the other is at min intensity

false

if a ball is 50 cm in front of a plane mirror, the distance between the ball and the image is

50

100

150

100

bigger wavelength equals

lower wave speed

in a double slit experiment the slit separation is doubled. the result is

halving of fringe spacing

when light travels from medium x to medium y,

speed snd frequency decrease

speed and frequency increase

speed and wavelength decrease

speed and wavelength increase

speed and wavelength decrease