1 depicts a  schematic view of the arrangement used for the
experimental study of the photoelectric effect It consists of an evacuated
glass/quartz tube having a thin photosensitive plate C and another metal
plate A Monochromatic light from the source S of sufficiently short
wavelength passes through the window W and falls on the photosensitive
plate C  (emitter) A transparent quartz window is sealed on to the glass
tube, which permits ultraviolet radiation to pass through it and irradiate
the photosensitive plate C