Experimental Results of Photoelectric Effect and Their Interpretation 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 photosensitive plate C and another metal plate A Monochromatic light from the source * of sufficiently short wavelength passes through the window W and falls on the photosensitive plate C (emitter). A transparent quartz window is sealed on the glass tube, which permits ultraviolet radiation to pass through it and irradiate the photosensitive plate C. The electrons are emitted by the plate C by the electric field created by the battery and are collected by the plate A (collector).
The battery maintains the potential difference between the plates C and A that can be varied. The polarity of the plates C and A can be reversed by a commutator thus, the plate A can be maintained at a desired positive or negative potential with respect to emitter C. When the collector plate A is positive with respect to the emitter plate C, the electrons are attracted to it. The emission of electrons causes flow of electric current in the circuit. The potential difference between the emitter and collector plates is measured by voltmeter (V) where as the resulting photocurrent flowing in the circuit is measured by microammeter (µA). The photoelectric current can be increased or decreased by varying the potential of collector plate A with respect to the emitter plate C. The intensity and frequency of the incident light can be varied, as can the potential difference V between the emitter C and the collector A
We can use the experimental arrangement of to study the variation of photo current with (a) intensity of radiation, (b) frequency of incident radiation, (c) the potential difference between the plates A and C, and (d) the nature of the material of plate C. Light of different frequencies can be used by putting appropriate **** filters or **** glasses in the path of light falling on the emitter C. The intensity of light is varied by changing the distance of the light source from the emitter
