Question

Two identical thick symmetrical biconvex lenses are put close together. The thickness of each lens equals the curvature radius of its surfaces, i.e. d = R = 3.0 cm. Find the optical power of this system in air.

Answer 1

Optical powers of the two surfaces of the lens are 

So, the power of the lens of thickness d,

and optical power of the combination of these two thick lenses,