1. an image of a distant object formed by a single converging lens ____. a. can be focused on a...

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1. An image of a distant object formed by a single converging lens ____. • A. can be focused on a screen. • B. can be projected on a wall. • C. is upside down. • D. is real. • E. all of the above.

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1. An image of a distant object formed by a single converging lens ____.

• A. can be focused on a screen.

• B. can be projected on a wall.

• C. is upside down.

• D. is real.

• E. all of the above.

1. An image of a distant object formed by a single converging lens ____.

• A. can be focused on a screen.

• B. can be projected on a wall.

• C. is upside down.

• D. is real.

• E. all of the above.

2. An image formed by a single diverging lens ____.

• A. is upside down.

• B. is larger than the object.

• C. can be projected on a wall.

• D. is virtual.

• E. all of the above.

2. An image formed by a single diverging lens ____.

• A. is upside down.

• B. is larger than the object.

• C. can be projected on a wall.

• D. is virtual.

• E. all of the above.

3. A magnifying glass is usually a ____.

• A. converging lens.

• B. combination of diverging and converging lenses.

• C. diverging lens.

3. A magnifying glass is usually a ____.

• A. converging lens.

• B. combination of diverging and converging lenses.

• C. diverging lens.

4. Which instrument is a human eye most similar to?

• A. camera

• B. microscope

• C. telescope

• D. slide projector

4. Which instrument is a human eye most similar to?

• A. camera

• B. microscope

• C. telescope

• D. slide projector

1. An object is placed 6.0 cm in front of a converging lens of focal length 4.0 cm. Draw a ray diagram to show the location and orientation of the image formed. What is its type and orientation?

• First draw a line parallel to the principle axis which refracts through the focal point.

• First draw a line parallel to the principle axis which refracts through the focal point.

• Then draw a line through the optical center of the lens. Where they cross is the image.

• This image is real and inverted (case 4). We use the equations to find the actual distance and size of the image.

2. The focal length of a double convex lens is 4.0 cm. An object 2.0 cm high is 10.0 cm from the lens. Draw a ray diagram of this situation. Calculate the location and size of the image. What is its type and orientation?

• First draw a line parallel to the principle axis which refracts through the focal point.

• First draw a line parallel to the principle axis which refracts through the focal point.

• Then draw a line through the optical center of the lens. Where they cross is the image.

• This image is real and inverted . We use the equations to find the actual distance and size of the image.

1 1 1 ------ = ------ + ------ f do di

1 1 1 ------ = ------ + ------ 4 10 di

di = 6.67 cm

hi di ------- = ------- ho do

hi 6.67 cm ------- = ----------- 2 cm 10 cm

hi = 1.3 cm, mag = 0.667

3. A double convex lens has a focal length of 5.0 cm. An object 0.75 cm high is 3.0 cm from the lens. Draw a ray diagram of this situation. Calculate the location and size of the image. What is its type and orientation?

• First draw a line parallel to the principle axis which refracts through the focal point.

• First draw a line parallel to the principle axis which refracts through the focal point.

• Then draw a line through the optical center of the lens. Where they cross is the image.

• Image is virtual, upright, and larger.

• Case 6, a magnifying glass.

1 1 1 ------ = ------ + ------ f do di

1 1 1 ------ = ------ + ------ 5 3 di

di = -7.5 cm

hi di

------- = ------- ho do

hi -7.5 cm --------- = ----------- 0.75 cm cm

hi = 1.88 cm, mag = -2.5

4. A concave lens has a focal length of 6.0 cm. An object is placed 7.0 cm from the lens. Draw a ray diagram of this situation. Calculate the location and size of the image. What is its type and orientation? What is the magnification of this lens?

• First draw a line parallel to the principle axis which refracts through the focal point.

• First draw a line parallel to the principle axis which refracts through the focal point.

• Then draw a line through the optical center of the lens. Where they cross is the image.

• This image is virtual, upright, and smaller. We use the equations to find the actual distance and size of the image.

1 1 1 ------ = ------ + ------ f do di

1 1 1 ------ = ------ + ------ -6 7 di

di = -3.2 cm

hi di

------- = ------- ho do

hi -3.2 cm --------- = ----------- ho 7 cm

mag = 0.46

5. What type of lenses are used to correct for farsightedness and nearsightedness?

• Farsightedness is corrected using a converging lens (convex).

• Nearsightedness is corrected using a diverging lens (concave).