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!

Electrical current and electrons

  1. Sep 3, 2015 #1
    Electrons flow from negative to positive. But everything in nature moves from higher potential to lower potential, i.e the charges should move from positive to negative but they don't?
  2. jcsd
  3. Sep 3, 2015 #2


    User Avatar
    Science Advisor
    Gold Member

    Potential is different from potential energy. To get the potential energy, you have to multiply the potential by the charge. Positive charges tend to move from high to low potential, but negative charges tend to move from low to high. Also, even regarding potential energy, nothing says that objects have to move toward lower potential energies. If I throw a rock upward, it moves to higher gravitational potential energies (at least for a bit).
  4. Sep 4, 2015 #3
    Look up again the definition of potential. You will see that is defined by using a positive charge as probe. So "low" and "high" potential according to standard definition are valid for a positive charge. If we use a negative charge, the low and high will change places. But rather than doing this re-definition we say that negative charges move from low to high potential.
  5. Sep 4, 2015 #4


    User Avatar
    Science Advisor

    Be aware that "negative" and "positive" definitions are a historical accident. They could just as well have been the other way around. All physics says is they are opposite.
  6. Sep 4, 2015 #5


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    Quite true. Electrons 'fall down' to the positive terminal (opposite sign) and their potential energy reduces. If, originally, early electrical Science had chosen a different sign for the charges, when electrons were found. they would have been given a Positive charge and this particular problem would not have presented itself to students. OTOH, the important principle that's involved, could have passed them by without them noticing.
  7. Sep 4, 2015 #6
    Thank You , It's quite clear now!
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Electrical current and electrons
  1. A current of electrons (Replies: 8)

  2. Current Electricity (Replies: 3)