Question

Why does the focal length decreases when the thickness increases

Answer 1

Ans ➡️ Because as we use A thin lens has a negligible thickness at this point compared to its focal length. If the thickness is more then the power of the lens is greater.If the power is greater then the tlength gets lesser as p = 1/f.so more the thickness less is the focal length and less the thickness more is the focal length.

Hope this helps ☺️☺️☺️