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Multiple choice Current through Bulb A

  1. Oct 19, 2012 #1
    1. The problem statement, all variables and given/known data

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    2. Relevant equations



    3. The attempt at a solution

    First I originally tried using kichhoff's rules, but didn't get far.

    What is throwing me off is they are giving me the current of the battery instead of the voltage. Since I know circuits in parallels all have the same voltage, I don't really know what to do.
     
  2. jcsd
  3. Oct 19, 2012 #2

    lewando

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    Gold Member

    Are you familiar with a current divider? Which path do you think allows more current--through A or through B-C?
     
  4. Oct 19, 2012 #3
    the path through A allows for current, since the path through B-C gets split up into two small currents.
     
  5. Oct 19, 2012 #4

    lewando

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    Gold Member

    Both paths allow for current. Path A allows for more current because it has less resistance. Knowing this you can solve the multiple choice question by process of elimination.

    Knowing what a current divider is and how to use is helpful: http://physics.eou.edu/courses/phys_223/sg2/node6.html

    If you want to solve another way, find the equivalent resistance [edit-- oops no resistance specified. So assume 1Ω per bulb. You will get a resulting voltage], then find the voltage, then find the individual currents. All three of these paths lead to the same answer.
     
    Last edited: Oct 19, 2012
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