JEE MAIN - Physics (2016 - 10th April Morning Slot - No. 5)
To determine refractive index of glass slab using a travelling microscope, minimum number of readings required are :
Two
Three
Four
Five
Wyjaśnienie
The refractive index is
$$\mu = {{{\mathop{\rm Real}\nolimits} \,depth} \over {Apparent\,depth}} = {{{\mathop{\rm Reading}\nolimits} \,3 - Reading\,1} \over {{\mathop{\rm Reading}\nolimits} \,3 - Reading\,2}}$$
Therefore, the minimum of three readings are required.