Question

experiment to find the refractive index of a prism

Answer 1

1.place a prism on a paper with triangular base and trace its boundaries,ABC
2.fix 2 pins T,S on one side
3.place the prism on the boundary ABC
4.looking through the other side fix 2 pins Q,R in such a way that all the 4 pins appear to be in the same line
5.remove the pins and mark their position
6.join TS and RS and extend them to meet the faces of the prism at P and O respectively.
7.join PO
8.let PN and ON be the normal at the point P and O respectively
9.let angle i be the angle of incidence and angle r be the angle of refraction
10.extend the incident ray TP forward and emergent ray RO backward,which meets at M forming the angle OML
11.measure the angle OML
12.this angle is called the angle of deviation.
         
          FORMULA OF REFRACTIVE INDEX 
                                   sin(A+Dm)/sin(a/2)
    now calculate the refractive index of prism