In finding out refractive index of glass slab the following observations were made through travelling microscope \( 50 \) vernier scale division \( = 49 \) MSD; \( 20 \) divisions on main scale in each \( \text{cm} \)
For mark on paper
MSR \( = 8.45 \, \text{cm} \), VC \( = 26 \)
For mark on paper seen through slab
MSR \( = 7.12 \, \text{cm} \), VC \( = 41 \)
For powder particle on the top surface of the glass slab
MSR \( = 4.05 \, \text{cm} \), VC \( = 1 \)
(MSR \( = \) Main Scale Reading, VC \( = \) Vernier Coincidence)
Refractive index of the glass slab is:
