1. Not finding help here? Sign up for a free 30min 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!

Circuit Problem -- With only a battery in the circuit, will current flow?

  1. Apr 19, 2016 #1
    1. The problem statement, all variables and given/known data
    Will current flow in an ideal circuit given that there is only an ideal battery in the circuit?

    2. Relevant equations
    V=IR

    3. The attempt at a solution
    Since there is no resistance through out the circuit no potential is dropped so no current flows
     
    Last edited by a moderator: Apr 19, 2016
  2. jcsd
  3. Apr 19, 2016 #2

    ProfuselyQuarky

    User Avatar
    Gold Member
    2016 Award

    Are you asking if whether a current will flow only if there is a battery?
     
  4. Apr 19, 2016 #3
    Yes
     
  5. Apr 19, 2016 #4

    ProfuselyQuarky

    User Avatar
    Gold Member
    2016 Award

    Of course. Batteries are the power supply of a circuit. How can there be current flowing through a circuit without any form of power connected to it?
     
  6. Apr 19, 2016 #5
    Thanks
     
  7. Apr 19, 2016 #6

    ProfuselyQuarky

    User Avatar
    Gold Member
    2016 Award

    Sure . . .

    Although I'm curious to know what made you think otherwise?
     
  8. Apr 19, 2016 #7

    gneill

    User Avatar

    Staff: Mentor

    Hold on, do you mean a circuit with a battery only, with its + terminal connected to its - terminal via an ideal wire?
     
  9. Apr 19, 2016 #8
    No current is flowing right? I was thinking the same but one guy said otherwise and gave no logic behind his reasoning
     
  10. Apr 19, 2016 #9
    And the battery doesnt even have internal resistance
     
  11. Apr 19, 2016 #10

    gneill

    User Avatar

    Staff: Mentor

    Then this is a case of an unrealizable circuit. The ideal battery will want to drive an infinite amount of current through the wire.

    You get a similar problem with an ideal current source with open terminals; it will want to create an infinite potential difference across the terminals in order to drive the required current.

    In both cases, in the real world, something's gotta give. Think: FLASH! BANG! SMOKE!
     
  12. Apr 19, 2016 #11
    No I am just asking why would current even flow when there's no potential difference across the circuit
     
  13. Apr 19, 2016 #12

    gneill

    User Avatar

    Staff: Mentor

    The ideal battery will attempt to make enough current flow in order to realize the battery's specified potential difference. With no resistance, it cannot accomplish this so the current heads off to infinity.
     
  14. Apr 19, 2016 #13
    For current to flow from one point to another point, there should be some potential difference but the whole circuit is on the same potential. Why would current flow then?
     
  15. Apr 19, 2016 #14

    ProfuselyQuarky

    User Avatar
    Gold Member
    2016 Award

    The OP didn't specify any of that o_O
    This sounds familiar
     
  16. Apr 19, 2016 #15
    The ideal battery's positive terminal is connected to its negative terminal by an ideal wire
     
  17. Apr 19, 2016 #16

    cnh1995

    User Avatar
    Homework Helper

    That is an unrealizable circuit, as gneill said earlier.
     
  18. Apr 19, 2016 #17
    I know but I am just curios to why would current even flow when there's no potential difference across the circuit
     
  19. Apr 19, 2016 #18

    cnh1995

    User Avatar
    Homework Helper

    Ideal battery tries to maintain a constant potential difference across its terminals. Ideal wires have zero resistance, hence, they try to have 0 potential difference across them. These two opposite behaviors make the circuit unrealizable. One good example gneill gave is of an open circuited current source. Similarly, you can't connect two ideal voltage sources in parallel and two ideal current sources in series. These are unrealizable circuits.
     
  20. Apr 19, 2016 #19
    Oh which means that my question is invalid?
     
  21. Apr 19, 2016 #20

    cnh1995

    User Avatar
    Homework Helper

    The situation in your question is invalid.
     
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: Circuit Problem -- With only a battery in the circuit, will current flow?
Loading...