Download Ch 14-15 Packet refraction interference diffraction

Ch 14 and 15
Refraction, Interference, and Diffraction of Light
NOTES:
Unit Objectives
What you should know when all is said and done:
1. Describe properties of waves that show how light behaves as a wave such as:
A) Refraction. Compare the speed of light through media with different optical densities
and explain why dispersion occurs.
B) Interference. Describe how interference patterns are formed from double slits,
diffraction gratings, and in thin films.
C) Huygen’s Principle and Diffraction. Explain some of the uses of diffraction.
2. Use the ray model of light and Huygens’ Principle to find the direction a light ray would travel
upon crossing the boundary between media with different optical densities (undergoing
refraction).
3. Find focal points for curved lenses, and relate to the center of curvature.
4. Trace ray diagrams for curved lenses to find images.
5. Distinguish between real and virtual images.
6. Explain how the eye works, and how vision is corrected.
7. Explain how optical instruments work (i.e. the camera, microscope).
8. Distinguish between spherical and chromatic aberration with lenses and understand how
each are corrected.
Worksheet 1: Ch 14 section 1 Refraction
(p. 484 – 489)
Vocabulary
A. Angle of Incidence
B. Angle of Refraction
C. Concave Lens
D. Convex Lens
F. Index of Refraction
G. Magnification
H. Optically Dense
I. Refraction
1. ______ The bending of light at the boundary between two media.
2. ______ A transparent refracting device that is thinner in the middle than at the edges.
3. ______ If the angle of refraction is smaller than the angle of incidence, the medium in which
the angle is smaller is more _____.
4. ______ The angle that a refracted ray makes with the normal.
5. ______ For light going from a vacuum into another medium, the constant n is the ____.
6. ______ A transparent device that cause light rays to converge.
8. ______ The angle that an incoming beam makes with the normal.
9. ______ The ratio of the size of an image to the size of the object.
11. Which labeled line represents the incident ray? How can
you tell?
Medium 1
C
12. Which line represents the refracted ray? How can you tell?
B
F
13. Which line represents the boundary between two media?
14. Which line represents the normal? How can you tell?
Medium 2
A
E
15. Which labeled angle represents the angle of incidence?
H
G
16. Which labeled angle represents the angle of refraction?
17. Which angle is greater: the angle of incidence or the angle of refraction?
18. Which medium is more optically dense? Which has the lower index of refraction?
19. When light passes into a medium in which it travels faster, the light will refract ________ the
normal. When light passes into a medium in which it travels slower, light will refract ________
the normal.
A) towards, away from
B) away from, towards
20. When light passes into a medium that is more optically dense, the light will refract ________
D
the normal. When light passes into a medium that is less optically dense, the light will refract
________ the normal.
A) towards, away from
B) away from, towards
22. In
eachdiagram,
diagram,
draw
the "missing"
ray incident
(either incident
or in
refracted)
in order to show
11.
In each
draw
the "missing"
ray (either
or refracted)
order to appropriately
that the direction
bending
is towardsof
or bending
away fromisthe
normal. or away from the normal.
appropriately
showofthat
the direction
towards
Light, Refraction and Lenses
12. A ray of light is shown passing through three
consecutive layered materials. Observe the direction
of bending at each boundary and rank the three
materials (A, B and C) in order of increasing index of
refraction.
<
smallest
<
largest
13. Arthur Podd's method of
fishing involves spearing the
fish while standing on the
shore. The apparent location
of a fish is shown in the
diagram below. Because of
the refraction of light, the
observed location of the fish is
different than its actual
location. If Arthur is to
successfully spear the fish,
must he aim at, below, or
above where the fish appears
to be? __________ Explain.
© The Physics Classroom, 2009
Page 4
WS 2: Ch 14 section 1 Index of Refraction
(p. 484 – 489)
1. Every transparent material is characterized by a unique index of refraction value (n). The
index of refraction value is a numerical value that provides a relative measure of the speed of
light in that particular material. Light travels __________________ (fastest, slowest) in media
with a higher index of refraction value.
2. The speed of light (v) in a material is determined using the speed of light in a vacuum (c) and
the index of refraction (n) of the material. Calculate the speed of light in the following materials.
n = c / v = (3.00 x 108 m/s) / v
A) water (n = 1.33):
B) glass (n = 1.50):
C) ice (n = 1.31):
D) diamond (n = 2.42):
3. Which of the following affects the index of refraction?
A) The angle of incidence
B) the nature of the transparent medium
C) The wavelength of light
D) All of the above
4. _______ is the bending of light (or change in direction) as it travels from one medium to
another.
A) Reflection
B) Index of refraction
C) Dispersion
D) Refraction
5. For light going from a vacuum into another medium, the constant n is the ____.
A) Reflection
B) Index of refraction
C) Dispersion
D) Refraction
6. If light slows down when going through a medium, it can be said that the medium has a high
A) Reflection
B) Index of refraction
C) Dispersion
D) Refraction
7. The relationship between the angles of incidence and refraction with the index of refraction of
2 materials is called ______________________ law.
WS 3: Ch 14 section 2 Thin Lenses
(p.490 – 497)
1. Use refraction principles to sketch an approximate path of light as it enters and exits the lens.
Think FST (fast to slow = toward) and SFA (slow to fast = away). Trace the path of the rays into,
through and out of the lens. Repeat the procedure for the light rays exiting the lens and trace
the emerging light rays. Place arrowheads on all light rays.
Light, Refraction and Lenses
Name:
Lenses
Read from Lesson 5 of the Refraction and Lenses chapter at The Physics Classroom:
2. Explain why lenses (like the one on the http://www.physicsclassroom.com/Class/refrn/u14l5a.html
left above) are called "converging" lenses.
http://www.physicsclassroom.com/Class/refrn/u14l5b.html
http://www.physicsclassroom.com/Class/refrn/u14l5c.html
Connection:
Refraction
and Lenses:
sublevel 7
3. Converging lensesMOP
are _____
at the center
and _____
at the edges.
A) thickest, thinnest B) thinnest, thickest
1.
Converging lenses are _____ at the center and _____ at the edges.
a. thickest, thinnest
b. thinnest, thickest
4. Diverging lenses are _____ at the center and _____ at the edges.
lenses are _____ at the center and _____ at the edges.
A) thickest, thinnest 2. B) Diverging
thinnest, thickest
a. thickest, thinnest
b. thinnest, thickest
Consider the diagramConsider
at the right
in answering
the next
two questions.
the diagram
at the right
in answering
the next two questions.
5. List the letters of all3. theList
converging
lenses.
the letters of all the converging
lenses.
6. List the letters of all4. theList
diverging
lenses.
the letters
of all the diverging
lenses.
'
For each statement below,
write
true orprinciples
rewrite the
italicized
part to make
theofstatement
true. and exits the lens. T
5. Use
refraction
to sketch
an approximate
path
light as it enters
7. __________________ FST
A convex
lens
can
be
used
as
a
magnifying
glass.
and SFA. Trace the path of the rays into, through and out of the lens. Repeat the procedu
the light rays exiting the lens and trace the emerging light rays. Place arrowheads on all light r
8. __________________ When a lens is used as a magnifying glass, the object is placed
outside the focal point.
9. __________________ Images produced by convex lenses are always real.
10. __________________ The images produced by concave lenses are always inverted.
11. __________________ A concave lens is thinner in the center than at the edges.
12. __________________ Concave lenses refract rays so that the rays converge.
#1:
#2:
#3:
10. State the three rules of refraction for diverging lenses:
13. Identify the following statements as being either true (T) or false (F).
#1: A) If reflected or refracted rays diverge, there is no image.
_______
_______ B) If an object is located in front of a focal point, there is no image.
#2: C) Virtual images cannot be seen.
_______
_______ D) All images are formed by the actual convergence of reflected or refracted light.
#3: E) Just three rays of light from an object can intersect at the image location.
_______
14. The
belowdepict
depictthe
the
refraction
of light
through
various
lenses.
Circle
the diagrams
11.
The diagrams
diagrams below
refraction
of light
through
various
lenses.
List the
diagrams
that
show the
of of
light.
_________
thoseshow
whichthe
show
the improper
refraction
of
that show
theproper
properrefraction
refraction
light.
For thoseFor
which
improper
refraction
of light,
light,
either
correct
the diagrams
by showing
the proper
refracted
or explain
what
is wrong
either
correct
the
diagrams
by showing
the proper
refracted
rays rays
or explain
what
is wrong
with
with the refracted
the refracted
rays. rays.
© The Physics Classroom, 2009
Page 10
WS 4: Ch 14 section 2 Ray Diagrams with lenses
(p. 490 – 497)
Light, Refraction and Lenses
1. The diagram below shows an arrow object positioned in front of a converging and a diverging
lens. Three incident rays are shown. Construct the corresponding refracted rays. Show
8. The diagram below shows an arrow object positioned in front of a converging and a diverging lens.
arrowheads.
Three incident rays are shown. Construct the corresponding refracted rays. Show arrowheads.
9.
State the three rules of refraction for converging lenses:
#2:
#2:
2. State the three rules of refraction for converging lenses:
#1: #1:
#3:
#3:
Light, Refraction and Lenses
10. State the three rules of refraction for
diverging lenses:
Name:
#1: the three rules of refraction for diverging lenses:
3. State
Ray Diagrams for Converging Lenses
#1:
Read from Lesson 5 of the Refraction and Lenses chapter at The Physics Classroom:
#2:
#2:
http://www.physicsclassroom.com/Class/refrn/u14l5da.html
http://www.physicsclassroom.com/Class/refrn/u14l5db.html
MOP Connection:
Refraction and Lenses: sublevels 8 and 9
#3:
#3:
11.
For the following lenses and corresponding object positions,
construct ray diagrams. Then describe the Location of the image,
Orientation (upright or inverted) of the image, the relative Size of
the image (larger or smaller than object), and the Type of image
The diagrams below depict the refraction
of light
various
lenses.
the diagrams that
(real or virtual).
For through
Case 4, merely
construct
the List
ray diagram.
show the proper refraction of light. _________ For those which show the improper refraction of
3. DRAWING
RAY
DIAGRAMS
FOR
CONVEX
LENSES.
Use
therays
rules
above
to
dray
ray of travel of the ray.
light, either
correct
the diagrams
byNOTE:
showing
the
proper
or
explain
what
wrong
1) All
light
rays refracted
have
arrowheads
which
indicate
theisdirection
with the
rays.
2) Always
in the image once located (an arrow is a good representation).
diagrams
andrefracted
complete
the “LOST” description
of thedraw
image.
3) Exactness counts. Use a straight-edge and be accurate.
Case 1: If the object is located
beyond 2F:
Case 1: If the object is located beyond 2F:
Description of Image:
Location:
______________________________
O: Upright or Inverted
S: Magnified or Reduced
T: Real or Virtual
Description of Image:
Location:
O: Upright or Inverted
S: Magnified or Reduced
T: Real or Virtual
Light, Refraction and Lenses
Description of Image:
Case 3: If the object is located between 2F and F:
Location:
O: Upright or Inverted
Case 2: If the object is located between 2F
Case 4: If the object is located at F:
and F:
S: Magnified or Reduced
T: Real or Virtu
Description of Image:
Location:
_________________________________
O: Upright or Inverted
S: Magnified or Reduced
T: Real or Virtual
Description of Image:
Location:
O: UprightRequired
or Inverted
S: Magnified or Reduced
No Description
Case
If the
object
is located
at F: F and the lens:
Case
5: 4:
If the
object
is located
between
Case 3: If the object is located between F and the lens:
T: Real or Vi
Name:
Description of Image: Light, Refraction and Lenses
Location: _________________________________
O: Upright or Inverted
Ray Diagrams for Diverging Lenses
S: Magnified or Reduced
T: Real or Virtual
Read from Lesson 5 of the Refraction and Lenses chapter at The Physics Classroom:
http://www.physicsclassroom.com/Class/refrn/u14l5ea.html
http://www.physicsclassroom.com/Class/refrn/u14l5eb.html
MOP Connection:
Refraction and Lenses: sublevels 10 and 11
For the following lenses and corresponding object positions, construct
ray diagrams. Then describe the Location of the image, Orientation
(upright or No
inverted)
of the image,
the relative Size of the image (larger
Description
Required
Description
ofand
Image:
or smaller
than object),
the Type of image (real or virtual).
Case 5:
If the object is located between F and the lens:
Location:
O: Upright
or Inverted
or Reduced
T: Real or Virtu
4. DRAWING RAY DIAGRAMS FOR
CONCAVE
LENSES. UseS:theMagnified
rules above
to dray ray
All light rays
haveimage.
arrowheads which indicate the direction of travel of the ray.
diagrams and complete the NOTE:
“LOST” 1)
description
of the
2) Always draw in the image once located (an arrow is a good representation).
3) Exactness counts. Use a straight-edge and be accurate.
©1:The
Physics
Classroom,
2009
Case 1: If the object is Case
located
away
the lens:
Iffar
the
objectfrom
is located
far
away from the lens:
Description of Image:
Location: ______________
O: Upright or Inverted
S: Magnified or Reduced
T: Real or Virtual
Description of Image:
Location:
O: Upright or Inverted
S: Magnified or Reduced
T: Real or Vi
Description of Image:
Location:
© The Physics Classroom, 2009
O: Upright or Inverted
S: Magnified or Reduced
T: Real or Virtual
Description of Image:
Location:
O: Upright or Inverted
S: Magnified or Reduced
T: Real or Virtual
Case 2: If the object is located nearby the lens:
Case 2: If the object is located
nearby the lens:
Description of Image:
Location: ________________
O: Upright or Inverted
S: Magnified or Reduced
T: Real or Virtual
Description of Image:
Location:
5. Several statements about images
are given below. Identify which optical device applies to the
given statement. Place the appropriate
marks
in the blanks.S:Mark
all thatorapply.
O: Upright
or Inverted
Magnified
Reduced
T: Real or Virtual
A = plane mirrors
B = concave mirrors
C = convex mirrors
D = converging lenses
E = diverging lenses
______________ a. Are
of producing
images.
© capable
The Physics
Classroom,real
2009
______________ b. Only produce virtual images.
______________ c. Are capable of producing enlarged images.
______________ d. Can only produce images which are smaller than the object.
______________ e. Capable of producing images the same size as the object.
WS 5: Ch 14 section 2 Eyeglasses and contact lenses
(p.498 -501)
1. What type of vision impairment is represented in the diagram below? How is this corrected?
2. What type of vision impairment is represented in the diagram below? How is this corrected?
3. What is astigmatism and how is it corrected?
4. What happens to your vision as you age? How is this corrected?
5. Both compound microscopes and refracting telescopes use ____________________________
6. High quality cameras use both _______________________ and ______________________ lenses to
minimize _______________________________. (p.500)
WS 6: Ch 14 section 3 Optical Phenomena
(p. 502 – 507)
1. __________________________________________describes the incident angle that causes a
refracted ray to lie along the boundary of a substance.
2. __________________________________________is when light passes form one medium to a less
optically dense medium at an angle so great that there is no refracted ray.
3. The complete reflection that takes place within a substance when the angle of incidence of light striking
the surface boundary is greater than the critical angle is called
A) critical angle B) index of refraction
C) complete internal reflection D) dispersion
4. The angle of incidence at which the refracted light makes an angle of 90 degrees with the normal is
called
A) critical angle B) index of refraction
C) complete internal reflection D) dispersion
5. Light will undergo total internal reflection only when it is _______. Choose two.
A) in the less dense medium traveling towards the more dense medium
B) in the more dense medium traveling towards the less dense medium
C) in the medium where it travels slowest, moving towards the medium where it travels fastest
D) in the medium where it travels fastest, moving towards the medium where it travels slowest
Complete the following blanks by answering questions #6 and #7: The critical angle is the angle of (#6)
that causes light to (#7) .
6. Referring to the statement above:
A) incidence
B) refraction
C) reflection
7. Referring to the statement above:
A) cross the boundary without refracting
B) undergo refraction at the same angle as the angle of incidence
C) refract at an angle of refraction of 90 degrees
D) reflect at the same angle as the angle of incidence
8. Examples of the use of total internal reflection are____________________________________ and
_________________________________
9. A mirage is produced by ______________________light rays in the atmosphere when there are large
_________________________________________between the ground and the air.
10. _______ is the separation of light into its spectrum of colors because light waves of different
wavelenghts change speed by different amounts when going through transparent materials.
A) Reflection
B) Index of refraction
C) Dispersion
D) Refraction
11. When entering a new transparent medium, blue wavelengths are bent _________(more/less) than red
wavelengths, causing dispersion.
12. Describe the three physics principles that cause rainbows to appear.(p.506)
1)
2)
3)
10. Describe two lens imperfections: chromatic aberration and spherical aberration. (p.507)
Wave Interference (Qualitative)
1. The intersection of two crests is shown. Sketch the position of these two crests a short time later
and indicate the direction of the movement of the intersection.
WS 7: Ch 15 section 1 Interference (p. 520 – 525)
(See also physicsclassroom.com “2 point source interference” lesson 1b)
2. The 1.
following
wave frontbetween
model represents
crestsofastwo
darkorlines.
marksisshowing
the outward
The correlation
the phases
moreThe
waves
called ______________.
This is
propagation
arephase
left outdifference
for clarity. between two waves is ___________________. This can only
when the
happen if both waves have the same ____________________.
C
When 2 waves overlap and areAprojected onto a screen, an __________________ pattern
appears. A point on the screen where two ____________ meet results in a bright fringe and a
point on the screen where two _________________
meet results in a dark fringe..
B
2. The pattern below shows two wave sources overlapping.
Describe the interference occurring at points A, B, and C.
A) If the double crests define a maximum line and the combination of a crest and a trough
define a minimum or node line, what does a double trough define?
3. If the double crests define a maximum line and the combination of a crest and a trough define a
minimum or node line, what does a double trough define? Show with diagrams.
B) On the pattern below draw the minimum lines (antinodal lines). Where the lines come out the
4. On the
drawfirst,
the maximum
linesthird
(antinodal
Where
lines(7
come
outtotal)
the top
toppattern
label below
the zero,
second and
orderlines).
lines on
eachtheside.
lines
label the zero, first, second and third order lines on each side. (7 lines total)
S1
C)Instruction
If this pattern
©Modeling
Programwere
2008
S2
two coherent light
a screen,
describe
1 sources projected onto
L2-Wave
Model ws
4a v4.0 what you
would see at the positions you marked.
8. a. For each of the lettered points on the interference pattern below answer these questions: How
3. The diagram
showfrom
two each
waves
interfering
withmany
eachwavelengths
other.
many below
wavelengths
source
is it, by how
do the two paths differ and
whether
there
constructive or
or destructive
at the point.
A) Label each
point
as is
constructive
destructiveinterference
interference.
A
C
B
F
E
D
S2
S1
Letter Wavelengths from
Wavelengths from S2
S1Constructive or Destructive
Location
Interference?
A
B
A C
B D
E
C F
Difference
Location
Constr or Destr
Constructive or
Destructive
Interference?
D
E
F
b. Explain in a sentence how the path difference between a point and the waves sources
4. Rainbow patterns
on “thin films” of transparent material such as an oil spill or a
determinescan
the be
typeseen
of interference.
sop bubble. This occurs because of (see physicsclassroom.com “thin film interference” lesson
1C)
A) refraction and dispersion of the white light into all colors of the rainbow
B) diffraction
C) reflection of colors from different surfaces
D) interference of light waves reflecting off the top and bottom surfaces of the film
9. This question is on the next page, there was not room for it here.
5. When you see streaks of color on the surface of a bubble or thin film of oil, this is called
________________________________________.
©Modeling Instruction Program 2008
3
L2-Wave Model ws 4a v4.0
WS 8: Ch 15 section 2 Diffraction (p. 526 – 533)
1. The bending of a wave when encountering an obstacle, opening, or edge is called
________________________.
2. An interference pattern, like the one produced with double slit interference, is produced when
light passes through a single narrow slit. This is called a _________________________ pattern,
and is evidence of light interfering with itself. In order to understand this phenomena, we invoke
__________________________ principle, which states that a single slit can be viewed as a
source of multiple point sources (wavelets) of light. In other words, light from ________ portion
of the slit can interfere with light from _________________ portion of the slit.
3. Diffraction becomes more evident as the width of the slit is ________________________.
4. In diffraction, longer waves tend to bend ________________(more/less) than shorter waves.
For this reason, ___________________ waves are best suited for communication around
buildings and mountains.
5. Diffraction is the reason why the edges of shadows ___________(are/aren’t) sharp.
6. Diffraction gratings are used inside ______________________ to disperse white light in
order to see characteristic wavelengths that are unique to each ____________________.
Sketch the interference of light with itself through a single slit using Huygen’s principle of
wavelets.