Question

two thin lenses are put close to eachother,focal length of the combination​

Answer 1

focal length of the combination, F=F1+F2

Answer 2

Answer:

f1 + f2 = F...

Explanation :

1)less than small focal lenght

2) more than bigger focal length

3) equal to arthmatical average of focal lenght

4) equal to geometrical average of focal length

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