Energy and momentum of electromagnetic waves/photons.
(a) In a photoelectric experiment, light with a wavelength of 250 nm hits a certain material. When a negative potential of 0.48 volt is applied there is no more current while a saturation current Is is recorded at positive voltages. From this information
(1) nd what the material is made of and
(2) deduce what the cuto wavelength is for this experiment. Also,
(3) what will the stopping potential be if the wavelength is changed to 200 nm? Finally,
(4) what would the saturated current be if the intensity of the light was doubled for the 250 nm case?
(b) An electron initially nearly at rest is hit with an x-ray. The scattered radiation is at a 45 from the incident direction. The scattered radiation has a wavelength of 0.01 nm. From this information,
(1)find the wavelength of the incident radiation and
(2) find the energy given o to the scattered electron, in eV. Finally
(3) find the minimum potential drop, in volts, that had to be used to accelerate the electrons from rest to produce the incident x-ray. What is the ratio of the resulting energy of the accelerated electrons to the energy given o to the electron in the scattering of the x-ray (using eV for the energies involved would be a good idea).