a. Two thin lenses of focal lengths f1 and f2 separated by a distance d have an equivalent focal length of 40 cm. The co

[answerhappygod]

a. Two thin lenses of focal lengths f1 and f2 separated by a
distance d have an
equivalent focal length of 40 cm. The combination satisfies the
conditions
for minimum spherical aberration and is also achromatic. Find the
values of
f1, f2 and d. Assume that both the lenses are of the same material.
[2+2+2]