3  PHOTOELECTRIC EFFECT
11 3 1  Hertz’s observations
The phenomenon of photoelectric emission was discovered in 1887 by
Heinrich Hertz (1857-1894), during his electromagnetic wave experiments In his experimental investigation on the production of electromagnetic
waves by means of a spark discharge, Hertz observed that high voltage
sparks across the detector loop were enhanced when the emitter plate
was illuminated by ultraviolet light from an arc lamp