A W incandescent light bulb converts approximately % of the electrical energy supplied to it into visible light. Assume that the average wavelength of the emitted light is l = nm, and that the light is radiated uniformily in all directions.

a) What is the energy of each photon in eV?

E = eV

b) How many photons per second would enter an aperture of area A = cm² located a distance D = m from the light bulb?

N = photons/s

c) Suppose, instead, that the average photon wavelength is nm. How many photons per second would enter the aperture?

N' = photons/s