Blog 10

As I walked to my computer, I noticed that my parent's room's lights were controlled by a dimmer.  A dimmer is a type of switch that allows for lights to be turned on at different brightnesses.  How they work is through the amount of resistance they provide to the circuit.  The normal equation for resistance is R=(rho)(L)/A.  As can be seen by this equation, the amount of resistance would be increased if the lenght of the circuit was increased.  By moving the switch up, we decrease the length, therefore decreasing the amount of resistance.  Since the amount of resistance is decreased, the amount of current is increased (ohms law).  This means that the power is now increased (P=IV).  And, as the power increases, the light bulbs become brighter.  This can be seen by the pictures below.  I never knew how a dimmer worked, and thanks to physics I now do.