1. A certain laser transition emits6.37×1015 quants per second per square meter. Calculate the power out put in joule per square metre per second. Given? = 632.8 nm.2. How many photons per minute are emitted by the source if a 1000W power source emits green light at a wavelength ?=5500A°.3. find the orbital angular momentum changes by when a hydrogen atom emits a photon of energy 12.1eV
