Determination of Refractive Index of a liquid using Lensmakers’ formula

Rabindranath Chattopadhyay

Haripal G.D.Institution,Hooghly,WB & Indian centre for space Physics,Kolkata

Abstract : Mathematical formula for the determination of focal length of a lens or a combination of lens can be found out from a set of interface equations properly set and arranged.Such a formula is derived particularly for thin lens.A compound lens,made of a pair of thin convex glass cover enveloping a liquid (water and glycerine separately in our experiment ) and are glued to each other is prepared and used as a compound liquid lens. The interface equation-based thin lens formula is then applied to the cases of two such lenses and thenmanipulating the experimentally found out value of focallength in respective cases the refractive indices (r.i.s) arefound out. Introduction: