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Q & A: The lens formula

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Most recent answer: 04/13/2013
Q:
The formula 1/f=1/u+1/v ,is derived for only one particilar situation.How can we use this formula for all cases?
- Varun (age 15)
India
A:
Hello Varun
I presume you are referring to the optical lens formula relating the image and object distances, u and v, with the focal length of a thin lens with focal length f.  A positive value for f corresponds to a converging lens whereas a negative value for f corresponds to a diverging lens.   This formula works for both cases.  

LeeH

(published on 04/13/2013)

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