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!

Help interpreting symbols of basic electric circuit

  1. Sep 14, 2014 #1
    Is asking for the voltage of a point in a wire (before/after a resister) the same as asking for the voltage across that resister? I understand voltage is relative..

    Here is the circuit:


    I can't wrap my head around what V1 represents. Other questions in this assignment specifically ask for the voltage across some element of the circuit. I just don't know how to interpret the notation of V1 as it is drawn in this circuit as I've never encountered it before.

    Any perspective on this would be appreciated.
  2. jcsd
  3. Sep 14, 2014 #2


    User Avatar
    Gold Member

    Yes (at least I THINK that's what you are asking)
    It is standard to take the bottom horizontal wire in a circuit as ground, so V1 just means the voltage from the labeled node to ground, which is the voltage across R2 and R3
  4. Sep 14, 2014 #3


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    It's a badly worded question.

    Voltages are indeed relative so to answer the question you will need to make an assumption. A reasonable assumption would be to choose 0V, Ground or battery -ve as the reference as Phinds suggests. Your answer should state that

    "V1 is ?V w.r.t the battery -ve terminal"

    In this case it's straightforward but in future watch out for exam questions that have the battery with the -ve terminal at the top.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Discussions: Help interpreting symbols of basic electric circuit
  1. Basic Circuits help (Replies: 2)