The following graphical sketch not drawn to scale was obtained when the refractive index (n) was plotted against the reciprocal of the wavelength (10.) for a given material. 1.70 l l l l l l | l l l l D 0 4.17 X 10'5 8.33 X 10'5 111. (m'l) Figure 1. Graphical sketch Given that n = A + B/lL where A and B are constants, determine the value of B from the graphical sketch shown in gure 1