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Voltage Divder Rule?

  1. Jan 7, 2007 #1
    I know the current divider rule. I want to know the Voltage Diver RUle in parrellel circuits.

    Suppose we have 4 resistors of 2 Ohms in parrellel. The source is 10V. That means the total resistance is 1/2 Ohms and Tje current 20 Amps.If the current divies equally we have 5 amps thhrough each branch. 5 amps on each 2 Ohm resisitor means that there are 10V going across each resisto. But that doesn't add up because there is 10V at the source and the makes 40V across all the resistors. SO doe sthe voltage divide or stay at 10V for each resistor?
  2. jcsd
  3. Jan 7, 2007 #2


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    I think you answered your own question! The voltage is the same across each component in a parallel circuit.
  4. Jan 7, 2007 #3
    How is that? SO I could divid it a thousand times but still not lower the voltage below 10V?
  5. Jan 7, 2007 #4


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    Correct! However, what would happen to the current is a different matter...
  6. Jan 7, 2007 #5
    SO in a series the resistors loose alot of power to resistors ahead of them.
  7. Jan 7, 2007 #6


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    Well the power dissipated is a product of current and voltage. Since the current in a series circuit is constant through all resistors, the only variable that changes from resistor to resistor is the voltage drop across them. No its not the loosing power to resistances ahead of them, instead the bigger voltage drop would yield higher power dissipation.
  8. Jan 7, 2007 #7
    Think of it this way. An ideal voltage source is something that (by definition) maintains a constant voltage across it. It doesn't matter what you put between the terminals of the source, whether it's a bunch of resistors in parallel, a transistor, or even an entire computer: you'll always find that the voltage across the leads is the same.
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