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Homework Help: Voltage within circuits

  1. Mar 6, 2005 #1
    My teacher gave us claims for homework and we have to prove them. Im having trouble with these two:

    • the voltage across the ends of a wire with current in it is zero
    • it doesnt matter across which device (light bulb, resistor, etc.) you measure the voltage in a parallel circuit
  2. jcsd
  3. Mar 7, 2005 #2


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    Homework Helper

    For the first one, that is sort of a definition. In reality, there is a voltage drop across every part of the circuit, but across a wire it is very small. We usually pretend the wires are ideal, and that the drop is exactly zero.

    For the second one, use kirchoff's voltage loop law, that the total voltage drop around any closed loop in a circuit must be zero.
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