Fri February 04, 2011 By: Shrini Sugandha

what will happen when we will put a convex lens inside the water and concave lens inside the water"?

Expert Reply
Fri February 04, 2011
Dear student,
Convex lens or concave lens is put inside water, Water's refractive index is in between air's and glass's. Therefore there is smaller change in refractive index between water and glass than between air and glass. Therefore, when the lens is put in water, then the light ray is bent by smaller amount after refraction. Therefore the ray travels for longer distance before it meets the principal axis. In other words focal length is larger.
Hope this helps.
Thanking you
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