photoelectric threshold photoelectric transducer photoelectric tube photo-electric valve photoelectric voltage photoelectrochemical cell photoelectromotive force photoelectron photoelement photoemission photoemissive photoemissive cell photoemissive effect photoemitter photoemulsion photo engraving photofabrication photofission photoflash photoflash lamp |
photoelectric threshold предел на фотоефекта Търсената дума е намерена |