Question
Tue November 27, 2012 By: Thabitha Fernandez

1. Name an alloy of zinc used in simple voltaic cell. 2.Why is alumminium used in flash bulbs?

Expert Reply
Wed November 28, 2012
1. A voltaic cell uses differences in oxidation potential of two metals to generate an electric current.  The original voltaic cells were stacks of copper and zinc alternating, with an electrolyte between the pieces of metal.   Alloys were not used in these cells, just the pure metals.
 
2. Flashbulbs have placed between their terminals, a piece of tungsten or zirconium filament. This wire is covered with an explosive primer paste.  When current is applied, the wire heats up, igniting the paste, which then ignites the tin, aluminum or (in later years) aluminum wire (or wool).  An oxygen atmosphere would increase the brilliance of the flash.  Some bulbs were also filled with nitrogen gas to actually slow or delay the burn.
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