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: Calculate the current through each ideal battery

  1. Feb 13, 2008 #1
    1. (a) Calculate the current through each ideal battery in the figure. Assume that R1 = 1.0 Ω, R2 = 2.0 Ω, ε1 = 4.0 V, and ε2 = ε3 = 8.0 V. Take positive current as that flowing through the battery from - to +. (See diagram)

    I just need some guidance about how to set this problem up.

    I've tried applying the Junction rule, to give me I1 + I3 = I2

    And then the Loop rule to give:

    4.0 V - 1(I1) - 2(I2) - 8V - 1(I1) = 0

    8V - 1(I3) - 2(I2) - 8V - 1(I3) = 0

    Am I setting this problem up correctly and using the right equations?


    Attached Files:

  2. jcsd
  3. Feb 13, 2008 #2
    According to the problem, you should have taken I2 in the other direction. Either replace I2 by -I2 in all equations, or replace I2 by -I2 after you're done. Apart from that it's ok.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook