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91 is the highest grade while 75 is the lowest grade.
Best Project ( Website and Reflection
Paper).......all
Best Portfolio......

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From what material are curve mirrors made from?
How plane and curve mirrors formed images?
What are the types of curved mirrors?
State the mirror and magnification equation use to locate an image in curved mirrors.

n
1 n
2 n
1 n = 1
1
Bending angle depends on value of n
2

If we apply the laws of refraction to two prisms, the rays bend toward the base, converging light.
Parallel rays, however, do not converge to a focus leaving images distorted and unclear.
Two prisms base to base

Similarly, inverted prisms cause parallel light rays to bend toward the base
(away from the center).
Two prisms apex to apex
Again there is no clear virtual focus, and once again, images are distorted and unclear.

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A transparent object that refracts light rays, causing them to converge or diverge to create an image

In order for a lens to converge light it must be thicker near the midpoint to allow more bending.
Double-convex lens
Plano-convex lens Converging meniscus lens

In order for a lens to diverge light it must be thinner near the midpoint to allow more bending.
Double-concave lens
Plano-concave lens diverging meniscus lens

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A converging lens is thicker at the middle than it is at the rim
– The front of the lens is the side of the lens where the object is
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Converging lenses can produce real or virtual images

2 F F F 2 F
The focal points are equidistant from the center of the lens. That distance is the focal length of the lens.

Ray
Parallel Ray
Central Ray
Focal ray
From object to lens
From lens to image
Parallel to principal axis
To the center of the lens
Passes through focal point F
Passes through focal point F
From the center of the lens
Parallel to principal axis

Ray 1
2 F F F 2 F
The focal points are equidistant from the center of the lens. That distance is the focal length of the lens.

Images Created by Converging Lenses

Images produced by lenses
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An object infinitely far away from a converging lens will create a point image at the focal point
– i.e. light from the
Sun

Images produced by lenses
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As a distant object approaches the focal point, the image becomes larger and farther away

Images produced by lenses
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When the object is at the focal point, the light rays exit parallel to each other and the image is
“at infinity”
– i.e. a lighthouse or a searchlight

Images produced by lenses
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When the object is inside the focal point, the rays are drawn the same way but you must extend them backwards in order to find the image

Converging Lens: Objects inside the focal point
Draw lines extending backwards to form the image
2 F F F
These rays are diverging and won’t cross
2 F

Summary
Object position
>2F at 2F
Image
Position between F and 2F at 2F
Real or virtual real
Magnified or diminished
Inverted or erect diminished inverted real same size inverted between 2F and F at F
> 2F at infinity between F and lens real same side as object virtual magnified magnified inverted upright

Locate and describe the image below
Diverging Converging
2.

1.
2.
3.
A converging lens has a focal length of 17 cm. A candle is located 48 cm from the lens. What type of image will be formed, and where will it be located?
A plano-convex lens of focal length 5.0 cm is used in reading lamp to focus light from a bulb on a book. If the lens is 60.0 cm from the book, how far should it be from bulb’s filaments?
A toy of height 8.4 cm is balanced in front of a converging lens. An inverted, real image of height
23 cm is noticed on the other side of the lens.
What is the magnification of the lens?

• The focal length of particular lens depends both on the index of refraction n of its material relative to that of the medium it is in and on the radii of curvature R
1 and R
2
.
1/f = (n-1) ( 1/R1 + 1/R2)
• R is + if the surface is convex.
• R is – if the surface is concave.
• f is + for converging lens
• f is negative for diverging lens
• It does not matter which surface is considered as1 and 2.
27

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A meniscus lens has a convex surface whoe radius of curvature is 25 cm and a concave surface whose radius of curvature is 15 cm. The index of rafraction is 1.52. Find the focal length of the lens and wether it is converging or diverging.

1 p

1 q
 f
1
M
  q p

+ p Object distance for lenses q Image in back of the lens ( real) f Converging Lens
Image in front of the lens (virtual)
Diverging Lens

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Sherlock Holmes examines a clue by holding his magnifying glass (with a focal length of 15.0 cm) 10.cm away from an object. Find the image distance and the magnification.
Describe the image he observes. Draw a ray diagram to confirm your answers.

What kind of lens is a magnifying glass?
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Magnifying glasses produce enlarged images. Therefore, a magnifying glass is a converging lens.
 f = + 15 cm, p= +10 cm

1
 q f
1

1 p

1
15

1
10
 
1
30 q
 
30 cm
M
  q p
 

30 cm
10 cm
 
3
The image is virtual and upright

Magnifying Lens Ray Diagram
2 F F
Object
F 2 F
Notice that the image is located at 2F (30 cm) and it is also in front of the lens which is why q is negative.

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A diverging lens is thinner at the middle than it is at the rim
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A diverging lens has two focal points but only one focal length
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Diverging lenses only produce virtual images

2 F F F 2 F
The focal points are equidistant from the center of the lens. That distance is the focal length of the lens.

Diverging Lens Reference Rays
Ray
Parallel Ray
Central Ray
Focal ray
From object to lens
From lens to image
Parallel to principal axis
To the center of the lens
Proceeding toward back focal point, F
Directed away from focal point
F
From the center of the lens
Parallel to principal axis

Drawing the Rays
Ray 1
2 F F F 2 F

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Using a ray diagram, find the position and height of an image produced by a viewfinder in a camera with a focal length of 5.0 cm if the object is 1.0 cm tall and 10.0 cm in front of the lens. A camera viewfinder is a diverging lens.

Object
2 F F F 2 F
The image is about 1/3 of the object height (.33 cm). The image location is about 3 or 4 cm from the lens. So, q is approximately -3.5 cm.

1
 q
1 f

1 p
 
1
5

1
10
 
3
10 q
 
3 .
3 cm
M
 h h o i
  q p h i
 h o
(
 q ) p

1 cm ( 3 .
33 cm )
10 cm

.
33 cm

a. Identify and describe the parts of the human eye vital in seeing objects.
b. Describe how image is formed in the retina ( Ray diagram is needed).
c. Explain how the eye accommodates to see clearly both far and near objects.

a. Identify and describe the parts of the camera.
b. Describe how image is formed in the camera
(Ray diagram is needed) c. Similarities and differences of the camera and the human eye.

a. Myopia and its Causes and corrective lens
(w/ ray diagrams) b. Hyperopia eyes and its Causes and corrective lens (w/ ray diagrams) c. Presbyopia eyes and its Causes and corrective lens (w/ ray diagrams) d. Astigmatism eyes its causes and corrective lens (w/ ray diagrams)

a. Parts of the microscope and its function.
b. Image formation in objective and eyepiece lens w/ ray diagrams

a. Parts of the telescope and its function.
b. Image formation in objective and eyepiece lens w/ ray diagrams

Picture and its uses / function/s a. Periscope b. Endoscope c. Interferometer d. Spectrometer e. Sunglasses