A thin convex lens made from crown glass … has focal length …. When it is measured in two different liquids having refractive indices … and … it has the focal lengths … and … respectively. The correct relation between the focal lengths is :

Option B. By Lens maker's formula for convex lens

Geometrical Optics

JEE Main 2014 · Session, Shift 1 · Q7030

PhysicsMedium105×since 2002Q7030

A thin convex lens made from crown glass

\left( {\mu = {3 \over 2}} \right)

has focal length

f

. When it is measured in two different liquids having refractive indices

{4 \over 3}

and

{5 \over 3},

it has the focal lengths

{f_1}

and

{f_2}

respectively. The correct relation between the focal lengths is :