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Converging and diverging lenses

  1. Nov 29, 2003 #1

    I am reading over the topic of converging and diverging lenses, and I had a question relating to phenomena of image formation as seen through these. Based on the ray diagrams that are typically used (freshman physics) how does one conclude whehter or not an image is inverted or upright? I know that a real versus virtual images depends on whether or not you have a convergence of the rays upon the focal point, but I am not sure about the former. Any insight would be wonderful! Thank you!
  2. jcsd
  3. Nov 29, 2003 #2


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    Staff: Mentor

    Just look at the lines. If the line that was on the top ends up on the bottom, then the image is inverted.
  4. Nov 29, 2003 #3
    Thank you for the prompt response. It is very much appreciated!:smile: . If it isn't too much trouble, would you mind explaining how the size of the image is determined as well?
  5. Nov 30, 2003 #4
    Measure the distance between the top and bottom line where they leave the object, and between the top and botom line where they form the image. The ratio of the two dimensions tells you by how much the image is magnified or reduced.
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