(a) What is the energy of a 633-nm photon?

(b) Two helium-neon lasers both emit 633-nm photons. Laser A has a power rating of \(1.0 \mathrm{~mW}\), but laser \(\mathrm{B}\) has a power rating of only \(0.25 \mathrm{~mW}\). Why do the power ratings differ when the lasers emit the same wavelength of light?