ANS:D - 100 cm

Chromatic Aberration ? :

->For Single Lenses the focal length of blue light will be slightly shorter than that for red light is know as Chromatic aberration,

Spherical Aberration:

->In Real Spherical lenses these outer rays do not focus at exactly the same point because of spherical aberration,

F = Focal Length ,
P = 1/F power lenses.
1 diopter equal 100 c.m./1 m. What is Means Diopter:-

-> A dioptre (uk), or diopter (us), is a unit of measurement of the optical power of a lens or curved mirror,
-> which is equal to the reciprocal of the focal length measured in metres.

Slove:-
1/metres For example, a 3-dioptre lens brings parallel rays of light to focus at 1/3 metre.

(Right Answer- 1 Diopter egual 100 cm or 1 m.)