A student plots a graph of the angle of deviation ( ) versus the angle of incidence ( i ) for a monochromatic light ray passing through an equilateral prism. The lowest point on the plotted curve has coordinates (x, y) . If the refractive index of the prism material is 3 , what are the values of x and y respectively?

Step-by-step solution

The graph of the angle of deviation ( ) versus the angle of incidence ( i ) is a curve where the lowest point corresponds to the position of minimum deviation. At this lowest point, the coordinates (x, y) represent the angle of incidence at minimum deviation ( i_m ) and the minimum angle of deviation ( _m ) respectively. For an equilateral prism, the angle of the prism is A = 60^ . At minimum deviation, the angle of refraction is r = A 2 = 30^ . Using Snell's law to find the angle of incidence x = i_m : i_m = r i_m