47) Energy of a photon of green light of wavelength 5500 is

48) Wavelength associated with a photon having energy 4.14eV is

49) If the work function of a material is 2eV, then minimum frequency of light required to emit photo-electrons is

50) If the threshold wavelength of radiations required to eject a photoelectron from a metal surface is 6??10^?7?m, then work function of the metal is

51) If work function of a metal surface is 3.45 eV ,then maximum wavelength of a photon required to eject a photoelectron is