What do we expect from our light and shadow analysis Two sharp bright spots Two blurry bright spots One wide blurry bright spot One wide sharp bright spot Something else NEXUSPhysics Clicker Questions ID: 469607
Download Presentation The PPT/PDF document "Light: Wave model" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Light: Wave modelSlide2
What do we expect from our
light and shadow analysis?
Two sharp bright spotsTwo blurry bright spotsOne wide blurry bright spotOne wide sharp bright spotSomething else
NEXUS/Physics Clicker QuestionsSlide3
When we put light through a thin pair of slits,
we
get a pattern different than we would expect from our light and shadow ray-model analysis. The two slit pattern looks like this.
What will happen if we close one of the slits?
The pattern will get dimmer
but not change shape.
The pattern will become
one spot, like in the ray model.We still have stripes but different ones.Something else.
NEXUS/Physics Clicker QuestionsSlide4
It
’
s a crest (max) now…what about 2 seconds from now?It will be a crest (max)
It will be a trough (min)It will be zeroOther
Say T = 4 sec
NEXUS/Physics Clicker QuestionsSlide5
It
’
s a zeronow…what about 2 seconds from now?
It will be a crest (max)It will be a trough (min)It will be zeroOther
Say T = 4 sec
NEXUS/Physics Clicker QuestionsSlide6
Below is shown a
“
ripple” picture showing crests and troughs of the ripples of water coming from two slits in a mask at a particular instant. Crests are solid lines, troughs are dashed. The small star represents a cork. The cork will move: Not at all.Outward away from the slitsUp and down the same as with one source
Up and down twice as high as with one sourceUp and down half as high
as
with
one source
★
NEXUS/Physics Clicker QuestionsSlide7
Below is shown a
“
ripple” picture showing crests and troughs of the ripples of water coming from two slits in a mask at a particular instant. Crests are solid lines, troughs are dashed. The small star represents a cork. The cork will move: Not at all.Outward away from the slitsUp and down the same as with one source
Up and down twice as high as with one sourceUp and down half as high
as
with
one source
★
NEXUS/Physics Clicker QuestionsSlide8
A long straight
jetty has had two holes broken into it by a storm. A series
of wavefronts strike it giving rise to outgoing circular waves . A fisherman watching various boats for a while after this picture was taken notices that some of the boats oscillate up and down a lot as the waves pass them and some oscillate almost not at all. Rank order these boats by how much they oscillate
A > D > B > C
A > B > D > C
A = C > B > D
A = C > B = D
A = C > D > B = 0
C > A > B > D = 0Other
NEXUS/Physics Clicker QuestionsSlide9
path A
path B
point X
(on screen)
Following along path
A
at a fixed instant of time
Following along path
B
at an instant of time
starting from
top slit
starting from bottom slit
point X
Is the result
1. a maximum,
2. a minimum,
3. Zero or
4.
neither?
NEXUS/Physics Clicker QuestionsSlide10
path A
path B
point Y
(on screen)
Following along path
A
at a fixed instant of time
Following along path
B
at an instant of time
starting from top slit
starting from bottom slit
point Y
Is the result
1. a maximum,
2. a minimum,
3. Zero or
4.
neither?
NEXUS/Physics Clicker QuestionsSlide11
path A
path B
Point X
(on screen)
At a LATER TIME after the time shown below
starting from top slit
starting from bottom slit
Point X
At X the wave
1.
has a steady
maximum
,
2. oscillates,
3. is zero, or
4.
neither?
NEXUS/Physics Clicker QuestionsSlide12
path A
path B
point Y
(on screen)
starting from top slit
starting from bottom slit
point Y
At Y the wave
1.
has a steady
maximum
,
2. oscillates,
3. is zero, or
4.
neither?
At a LATER TIME after the time shown below
NEXUS/Physics Clicker QuestionsSlide13
The green interference fringes shown in the picture on the right are produced on a screen by putting a green laser beam with a wavelength of 550 nm through two identical slits. If the screen is 4 m from the slits, can
the
spacing between the slits be calculated? YesNo
NEXUS/Physics Clicker QuestionsSlide14
The green interference fringes shown in the picture on the right are produced on a screen by putting a green laser beam with a wavelength of 550 nm through two identical slits. If the screen is 4 m from the slits, can
you
find the spacing between the slits? YesNo
NEXUS/Physics Clicker QuestionsSlide15
If the
wavelength were reduced, what would happen to pattern on the screen?
It would not change.It would squeeze closer together.It would spread further apart.You can’t tell from the information given.
NEXUS/Physics Clicker QuestionsSlide16
If the
screen were moved closer to the slits, what would happen to pattern on the screen?
It would not change.It would squeeze closer together.It would spread further apart.You can’t tell from the information given.
NEXUS/Physics Clicker QuestionsSlide17
T
he figure shows what happens if you put white light through the same slit-screen system. W
hy are the different colors separated on either side of the center?
NEXUS/Physics Clicker QuestionsSlide18
A laser beam passes through a double-slit
forming an interference pattern.
If we cover one slit with a glass plate, the phase of the wave passing through the glass changes by 180° from what it would have been without the glass. How is the interference pattern changed? The pattern of alternating light and dark spots disappears leaving a single, wide, bright spot.
The pattern of alternating light and dark spots disappears leaving the screen dark.The pattern of bright spots spreads out.The pattern of bright spots gets closer together.The pattern reverses itself, bright becoming dark and vice versa.
NEXUS/Physics Clicker QuestionsSlide19
If
the wavelength is increased,
what will happen to the pattern?Get widerGet narrower
Stay the same
Something else
NEXUS/Physics Clicker QuestionsSlide20
If
the wavelength is decreased, what
will happen to the fringes (narrow peaks shown in red)?Fringes get widerFringes get narrowerFringes stay the sameSomething else
NEXUS/Physics Clicker QuestionsSlide21
If
the wavelength is reduced, what
will happen to the squash point (the point where the fringes are driven to zero – shown by the dark arrow)?Move toward the centerMove away from the centerStay the same
Something else
NEXUS/Physics Clicker QuestionsSlide22
When a laser is shone upon a double slit, a
closeup of the center of the pattern looks like the figure at the right. If one of the slits is covered (the left one) but the other slit remains open, what will
this part of the pattern look like? The same.The left side will be dark.The right side will be dark.The whole thing will be bright.The whole thing will be bright except for two dark bands at either side.Something else.
NEXUS/Physics Clicker QuestionsSlide23
If
the slit is made wider, what
will happen to the pattern?Get widerGet narrower
Stay the same
Something else
NEXUS/Physics Clicker Questions