clc 
// Given that
lambda = 4e-7 // wavelength of spectral line in meter
h = 6.62e-34 // Planck constant in J-sec
c = 3e8 // speed of light in m/sec
e = 1.6e-19 // charge on an electron in C 
// Sample Problem 3 on page no. 14.20
printf("\n # PROBLEM 3 # \n")
printf("Standard formula used \n")
printf(" E = h*c/lambda \n")
E = (h * c) / lambda
printf("\n Energy of photon is %e J.",E)