Optics basic question

IIT JEE 2015 Forum › Optics questions › Optics basic question

In the following figure, the space b/w the glass lenses is filled with water. We have to find the focal length of the system (radii of curvature, refractive indices given)

Now to calculate the focal length of the water lens, we use the lens makers formula-
1/f = (U-1)(1/R1 - 1/R2)
Why don't we substitute U as gUw instead of aUw as given in all books? Doesn't the light travel from glass to water?

#Physics #Optics

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2 Answers

1

Amit Dutta ·2011-07-27 06:05:49

gUw is taken into consideration only when the lens is immersed in water.here the system is in air.

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dbzgoku gohan ·2011-07-31 06:29:10

shouldnt the formulae be
1/f=(u_water
u_glass-1)(1r₁-1r_₂)

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