Question

a Biconvex lens is to be made from glass of refractive index 1.55, with both faces having same radius of curvature determine this radius of curvature if the focal length is 20 CM​

Answer 1

HELLO DEAR FRIEND

GIVEN FOCAL LENGTH = 20CM

RADIUS OF CURVATURE = 2 × FOCAL LENGTH.

==> 2 × 20 = 40CM

$\huge \bf \it \boxed{ = 40cm}$

HOPE IT HELPS YOU DEAR FRIEND THANKS