Worksheet
Thin Lens Equation #1: Converging Lenses
Directions:
Work these problems on notebook paper, boxing in your answers. Although polished rays diagrams are not required, sketches for each situation are recommended. Once all four problems are completed, make sure that your paper is signed and dated.
Some resources that you might find useful are:
resource lesson
on converging lenses
resource lesson
on the thin lens equation
resource lesson
on converging lens examples
PhET animation
on converging lenses
Refer to the following information for the next six questions.
A converging lens has a focal length of 20 cm.
If it is placed 50 cm from an object, how far from the lens will the image be formed?
Which
case
is this?
Case #1: object is located at infinity.
Case #2: object is located in region I.
Case #3: object is located on the line between regions I and II, exactly two focal lengths in front of the lens.
Case #4: object is located in region II.
Case #5: object is located on the line between regions II and III, exactly one focal length in front of the lens.
Case #6: object is located in region III.
Is it real or virtual?
real
virtual
Is it upright or inverted?
upright
inverted
What is the magnification?
Based on your magnification, is the image enlarged, reduced, or the same size as the object?
enlarged
reduced
the same size
Refer to the following information for the next six questions.
An object is placed 10 cm from a converging lens of focal length 5 cm.
How far from the lens will the image be formed?
Which
case
is this?
Case #1: object is located at infinity.
Case #2: object is located in region I.
Case #3: object is located on the line between regions I and II, exactly two focal lengths in front of the lens.
Case #4: object is located in region II.
Case #5: object is located on the line between regions II and III, exactly one focal length in front of the lens.
Case #6: object is located in region III.
Is it real or virtual?
real
virtual
Is it upright or inverted?
upright
inverted
What is the magnification?
Based on your magnification, is the image enlarged, reduced, or the same size as the object?
enlarged
reduced
the same size
Refer to the following information for the next six questions.
An object placed 30 cm from a converging lens forms a real image 60 cm from the lens.
What is the focal length of the lens?
Which
case
is this?
Case #1: object is located at infinity.
Case #2: object is located in region I.
Case #3: object is located on the line between regions I and II, exactly two focal lengths in front of the lens.
Case #4: object is located in region II.
Case #5: object is located on the line between regions II and III, exactly one focal length in front of the lens.
Case #6: object is located in region III.
Is it upright or inverted?
upright
inverted
What is the magnification?
Based on your magnification, is the image enlarged, reduced, or the same size as the object?
enlarged
reduced
the same size
If the object is 5 cm tall, how tall is the image?
Refer to the following information for the next six questions.
When a 5.0 cm tall object is placed 12 cm from a converging lens, an image is produced on the same side of the lens as the object, but 60 cm away from the lens.
What is the focal length of the lens?
Which
case
is this?
Case #1: object is located at infinity.
Case #2: object is located in region I.
Case #3: object is located on the line between regions I and II, exactly two focal lengths in front of the lens.
Case #4: object is located in region II.
Case #5: object is located on the line between regions II and III, exactly one focal length in front of the lens.
Case #6: object is located in region III.
Is it real or virtual?
real
virtual
Is it upright or inverted?
upright
inverted
What is the magnification?
How tall is the image?
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