If light of wavelength, 2 = 4000 A and intensity 100 W/m² incident on a metal plate of threshold frequency 5.5x10* Hz , what will be the maximum kinetic energy, and work function of photoelectron? (Take, h=6.6x10-3* J.s ). %3D

6. (30 points) Construct the energy level diagram for a singly ionized helium (Z = 2) up to the first six energy levels. Show proper energy in eV for each level. П n Anode Photoelectrons Metal specimen (a) An electron in a helium atom jumps from some initial orbit ni to some final orbit nf. If the photon emitted in the process is capable of ejecting photoelectrons from a metal specimen (work function 7.00 eV), determine nf. = (b) If a minimum stopping potential of Vo = 5.09 V is required to prevent the photoelectrons from hitting the anode, determine the value of ni.

3. Light of wavelength 500. nm is incident on a metallic surface. If the stopping potential for the photoelectric effect is 0.450 V, find (a) the maximum kinetic energy of the emitted electrons, (b) the work function, and (c) the cutoff wavelength. 11

Estimate the binding energy of electrons in magnesium, given that the wavelength of 337 nm is the longest wavelength that a photon may have to eject a photoelectron from magnesium photoelectrode. Electrons are bound to the magnesium with potential depth of at least eV.