Iron emits `K_alpha` X-ray of energy 6.4 keV and Calcium emits `K_alpha` X-ray of energy
Channel: Doubtnut
Date: 2020-07-05

Iron emits `K_alpha` X-ray of energy 6.4 keV and Calcium emits `K_alpha` X-ray of energy 3.69 keV. Calculate the times taken by an iron `K_a` photon and a calcium `K_a` photon to cross through a distance of 3 km.