<P> The two World Wars and the growing aviation industry gave impetus to further developments and refinements including such processes as hard chromium plating, bronze alloy plating, sulfamate nickel plating, along with numerous other plating processes . Plating equipment evolved from manually operated tar - lined wooden tanks to automated equipment, capable of processing thousands of kilograms per hour of parts . </P> <P> One of the American physicist Richard Feynman's first projects was to develop technology for electroplating metal onto plastic . Feynman developed the original idea of his friend into a successful invention, allowing his employer (and friend) to keep commercial promises he had made but could not have fulfilled otherwise . </P> <P> Electroplating is widely used in various industries for coating metal objects with a thin layer of a different metal . The layer of metal deposited has some desired property, which the metal of the object lacks . For example, chromium plating is done on many objects such as car parts, bath taps, kitchen gas burners, wheel rims and many others for the fact that chromium is very corrosion - resistant, and thus prolongs the life of the parts . It is also used in making expensive jewelry . </P> <P> The Hull cell is a type of test cell used to qualitatively check the condition of an electroplating bath . It allows for optimization for current density range, optimization of additive concentration, recognition of impurity effects and indication of macro-throwing power capability . The Hull cell replicates the plating bath on a lab scale . It is filled with a sample of the plating solution, an appropriate anode which is connected to a rectifier . The "work" is replaced with a Hull cell test panel that will be plated to show the "health" of the bath . </P>

Give two examples of the application of electroplating