Question: Two thin lenses with focal lengths of 16cm and 18cm respectively are placed 12cm apart. what is the effective focal length of this combination of lenses?(adsbygoogle = window.adsbygoogle || []).push({});

I used the formula:

1/f1+ 1/f2 = 1/f effective

My solution:

1/16 + 1/18 = 1/f effective

which gave me an effective focal length of 8.47cm.

Is this right or does the fact that they are put 12cm apart affect the effective focal length?

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# Homework Help: Basic lense question

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