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A PAIR OF PLATES



Can just a pair of plates(conductors) make an important component in all the gadgets and appliances we use daily?  Yes it is. 


    Imagine two metal plates separated by a small gap.  If one plate is charged positively using a battery, negative charge will be induced in the other plate since they are very close.  Both the plates hold charges and the electric field.  They act as a temporary storage of electricity or like a small battery.  When the plates are connected externally by a wire, they discharge and send a current.  This arrangement is called capacitor.  It has wide applications. 

     In a camera,  charges stored in the capacitor is released all at once triggering a 'flash of light'.  Since it act as a temporary storage between the source of electricity and the appliance, it can smooth out the fluctuations in the current and can supply a steady current.  

      Take two strips of aluminium foils (food packaging material).  Put a thin strip of white paper between them.  Roll them together.  Attach two pieces of wire to the two aluminium strips.  Wow!  You made a good capacitor(do not experiment).  

      The principle:  The two conductors should be separated by a non conductor.  The gap between the conductors should be as small as possible.  The area of the conductor should be as large as possible.  Then the capacitor will have good capacity.  

      Tiny cylinders in the circuit boards are capacitors.  We have large capacitors as well as capacitors built in silicon chips.  Charging and discharging is its main function.  So it appears everywhere in electronics.  

     Just a 'simple pair of conductors' is used in so many gadgets is a miracle in technology.     

     

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