1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

PD between 2 points

  1. Nov 8, 2007 #1
    1. The problem statement, all variables and given/known data
    a current of 2A is flowing from a to b.
    what is the potential difference between the points?


    hopefully my diagram makes sense.

    2. Relevant equations
    this is a really simple question and i cant answer it because im not understanding the whole concept.
    Does current (or anything) stay constant in a cicuit??
    do i follow the current round/thru circuit and do calcs along the way?
    so voltage after 3ohm-R = IR = 6V
    so 6V into 20V battery. now im stuck. it goes into neg term first so is that -20V?? please help somene! thanks

    3. The attempt at a solution
  2. jcsd
  3. Nov 9, 2007 #2


    User Avatar
    Homework Helper

    If you assume a battery of EMF E volt is connected across the a and b such that a end is +ve and b end is -ve. Apply loop law, and find E. If you get E +ve, signs of a and b correct. If you get E -ve, reverse the signs of a and b.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: PD between 2 points
  1. PD between +q and -q (Replies: 4)