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Homework Help: A Few Questions I Would Like to Endeavour to Ask

  1. Jun 15, 2009 #1
    Ok, I have a Physics exam in two days (on DC circuits) and I've pretty much done everything I've needed to. However, I am anticipating a few difficult problem solving questions, so just in case I would like to clarify a few things:

    1. Generally, if you had two or more sources of power supply (EMFs) in a circuit; how would you tackle the problem? Just a general formula or tactic would be appropriate?

    2. With regard to the voltage symbol in an EMF, does it matter how many lines you have or do a certain amount of lines denote a certain amount of voltage.

    3. This last question isn't really to do with problem solving, but rather, I've always wondered. In a DC circuit, does the current always travels from the negative side through a possible route and to the positive end of the power supply?
    Last edited: Jun 15, 2009
  2. jcsd
  3. Jun 15, 2009 #2


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    Homework Helper

    1) Use Kirchhoff's junction and loop rule.

    2)Do you mean the battery (smal -| big |+)? You cannot deduce the voltage over the battery's terminals from any lines/drawing.

    3)Current runs, conventionally, from the + terminal to the - terminal. The electron current itself, since electrons have negative charge, runs from the - terminal to the +terminal
    Last edited: Jun 15, 2009
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