A convex lens has 10cm focal length in air what is its focal length in water - Physics -

Question

A convex lens has 10cm focal length in air what is its focal length
in water?

Krishan Yadav · Accepted Answer

Dear Student,

Focal length of a lens is given by

f = μ1μ2-μ1(R1R2R2-R1)In air assuming lens made of glass10 = 11
5-1(R1R2R2-R1)10 =2 (R1R2R2-R1)-----eq1for water μ1 = 4/3f =43/(32-43) (R1R2R2-R1)f= 8 (R1R2R2-R1)-----eq2divide eq2 by eq1f=40 cm

Regards

A convex lens has 10cm focal length in air .what is its focal length in water?