Units And Measurements

In finding out refractive index of glass slab the following observations were made through travelling microscope 50 vernier scale division \(=49 \mathrm{~MSD} ; 20\) divisions on main scale in each \(\mathrm{cm}\)

For mark on paper

\(\text { MSR }=8.45 \mathrm{~cm}, \mathrm{VC}=26\)

For mark on paper seen through slab

\(\mathrm{MSR}=7.12 \mathrm{~cm}, \mathrm{VC}=41\)

For powder particle on the top surface of the glass slab

\(\text { MSR }=4.05 \mathrm{~cm}, \mathrm{VC}=1\)

(MSR \(=\) Main Scale Reading, VC = Vernier Coincidence)

Refractive index of the glass slab is :