Question

obtian an expression for effective focal length of two convex lenses in contact. 3 mark​

Answer 1

Answer:

Combined focal length of two thin lenses in contact is given by: F=f1+f2f1f2.

Explanation:

Answer 2

Answer:

f=f1+f2f1f2

Explanation:

let the focal lengths of the two lenses be f1 and f2

u1=OC1 and

v1 =I1 c1

u2 =c1 I1 which is approximately equal to c2 I1 and

v2 =c2I which is approximately equal to c1I