1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Optics question

  1. Sep 4, 2003 #1
    Compute the focal length in air of a thin biconvex lens (n=1.5) having radii of 20 and 40 cm. Locate and describe the image of an object 40cm from the lens.

    my answer:

    1/f = (n-1)(1/R1-1/R2)
    1/f = (1.5-1)(1/20-1/40)
    1/f = .5(.025)
    f = 1/.0125 = 80cm (convering lens because f is positive)

    Mt=-f/x0=-80/40=-2cm (Inverted image because Mt is negative)

    Did I use the correct equations?
     
  2. jcsd
  3. Sep 10, 2003 #2
    Looks O.K. to me.
    I should expect, if the object is only 40cm from the lens while the lense's focal length is 80cm, then the image should be upright and virtual, and magnified by a factor of 2.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Optics question
  1. Optics question (Replies: 2)

  2. Optics question (Replies: 1)

  3. Optic question (Replies: 0)

  4. Question on optics (Replies: 2)

  5. Optics question (Replies: 7)

Loading...