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Homework Help: Resistors and Brightness

  1. Mar 4, 2009 #1
    1. The problem statement, all variables and given/known data
    How do the bulb's brightness compare?

    Which ones will be brighter or dimmer?

    What will happen if a resistor is placed before Bulb 2?
    What will happen if a resistor is placed between Bulb 2 and 3?

    Does it matter if i place the resistor before or after the ammeter? Will it read the same?

    2. Relevant equations

    P = IV

    R = V/I

    3. The attempt at a solution

    I think all 3 bulbs will be at the same brightness because current and voltage are the same for both branches.

    Thanks for help me out!

  2. jcsd
  3. Mar 4, 2009 #2
    Are these identical bulbs? Are they standard incandescent bulbs?
  4. Mar 4, 2009 #3
    YES, they are.
  5. Mar 4, 2009 #4
    When lightbulbs are in a series, they do not receive as much current as the lightbulb in the parallel series. In other words, the brightnest depends on which lightbulb will receive the current.
  6. Mar 4, 2009 #5

    you mean that lightbulbs in series receive less current than those in parallel?

    Isnt that Current is the same throughout the whole series?

    and Total current in parallel circuit is the sum of all currents flowing thru all branches?
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