clc
//Chapter3
//Ex_1
//Given
lambda=450*10^-9 // in nm
h=6.6*10^-34 //in J s
e=1.6*10^-19 // in coulombs
c=3*10^8 //in m/s
E_ph=h*c/lambda //in J
E_ph=E_ph/e // in eV
disp(E_ph," Energy of blue photon in eV is")