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Homework Help: Difficulty with Parallel Batteries

  1. Apr 12, 2005 #1
    Hi everyone,

    I've tried searching over and over again in my textbook and online, but I can't seem to find anything about the specific nature of parallel batteries.

    So I have the following problem that I can't get anywhere with:

    There is a 6 ohms light bulb connected to two 1.5 V batteries that are in parrallel. Each battery has an internal resistance of 0.5 ohms.

    1. What is the current through the bulb? (No idea on the formula. :cry: )
    2. What is the terminal voltage across each battery? (No idea. :cry: )
    3. What is the power consumption of the bulb? (I'm guessing after finding the current, the power consumption will just be I^2*R?)
    4. By what factor have you shortened or lengthened the life of the batteries? (All I know is that the life is lengthened, but I have no idea what the formula is.)

    Thanks sooo much everyone for helping out!
  2. jcsd
  3. Apr 12, 2005 #2


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    Science Advisor
    Gold Member

    Here's a hint: The EMF across two parallel 1.5V batteries will be 1.5V.

    Do you really have no idea of what formula to use? You're trying to find the current, and you have voltage and resistance.
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