clear;
clc;
printf("\nEx4.2\n");
//page no.-156
//given
b=2.898*10^-3;.......//constant in m*K
T=2000;...............//temperature in kelvin

lambda=b/T.............//wavelength in m, relation by Wein's Law

printf("\nwavelength is 1.449 micron\n");
printf("\nWe know visible region is 0.4 micron to 0.8 micron, so this wavelength is beyond red colour of visible spectrum\n");