Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Calculating potential difference

  1. May 3, 2010 #1
    1. The problem statement, all variables and given/known data

    In a 50 V circuit with a 400 Ohm resistance and a 600 Ohm resistance in series; Point A is between the two resistors and point B is to the right of the 600 Ohm resistor. Charge is moving from right to left.

    2. Relevant equations


    3. The attempt at a solution
    The answer is supposed to be 30 V, but why isn't it 50 V?
    Last edited: May 3, 2010
  2. jcsd
  3. May 3, 2010 #2


    User Avatar
    Homework Helper

    In parallel? It seems, from the rest of the question and the answer, like they're in series.
  4. May 3, 2010 #3


    User Avatar
    Science Advisor
    Homework Helper

    Hi tmusgrove! :smile:
    How can it be 50 V ?

    That's the potential difference across both resistors. :wink:
  5. May 4, 2010 #4
    With TinyTim's reminder that the whole potential difference was 50, I could solve the problem. 600 Ohms and 400 Ohms = 1000 Ohms. 600 is 3/5 of 1000. 3/5 of 50 = 30. So, the answer is 30 V.
  6. May 4, 2010 #5


    User Avatar
    Science Advisor
    Homework Helper

    Yup! :biggrin:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook