Question

A. Refraction of Light - Snell's Law: (see Fig.1 in DL manual) when light travels from air (n = 1) into glass (n = 1.5), the refracted angles Or are smaller than the incident angles Oj. 1.(5 pts) Input the data from Table 1 in the manual into the Snell's law. xlxs spreadsheet. Sketch the graph of sine; vs. sin, on the figure given here. Label the axes. 2.(5 pts) Write the equation from the graph in the space given below: 3.(5 pts) Rewrite the above equation in terms of sin and sin, 4.(5 pts) What is the value of the slope? What does it represent?

Answer 1

The table for incident and refracted angles

Incident Angle Refracted Angle 5 3.2 10 6.6 15 10 20 13 25 30 16 19 35 22 40 24

The graph of for snell's Law (sinθi vs sinθr)

Snells Law 30 25 y = 0.6014x +0.6929 20 Refracted Angle Or (Degrees) 15 10 5 0 0 5 10 15 20 25 30 35 40 45 Incident Angle Di (Degrees)

2)The equation of line from the graph comes out to be

y= 0.6014x +0.6929,

3) Since y axis represents sinθr and x axis represents sinθi ,so

i.e. sinθr = 0.6014(sinθi ) + 0.6929

4) The slope comes out to be 0.6014.

From snells law, n1 sinθi = n2 sinθr

i.e. ${sin(\theta_{r})}=\frac{n_{1}}{n_{2}}{sin(\theta_{i})}$

Comparing this with the equation of line y=mx+c, the expected slope = n1/n2.

For n1=1 and n2=1.5, we get the expected value of slope as 1/1.5 = 0.667.

The slope represents the refractive index of air wrt to glass.

The inverse of slope would represent the refractive index of glass wrt air.