// Additional solved numerical questions  , Example(set 1)  12_b_3 , pg 349
Eg=0.8*1.6*10^-19   //bandgap  (in J)     (converting  eV  into  J)
h=6.625*10^-34     //plancks constant   (in  J s)
c=3*10^8       //speed of light   (in m/s)
lam=(h*c)/Eg     //wavelength
printf("wavelength of light emitted (in m)is=")
disp(lam)