What is charge conservation: Definition and 26 Discussions

In physics, charge conservation is the principle that the total electric charge in an isolated system never changes. The net quantity of electric charge, the amount of positive charge minus the amount of negative charge in the universe, is always conserved. Charge conservation, considered as a physical conservation law, implies that the change in the amount of electric charge in any volume of space is exactly equal to the amount of charge flowing into the volume minus the amount of charge flowing out of the volume. In essence, charge conservation is an accounting relationship between the amount of charge in a region and the flow of charge into and out of that region, given by a continuity equation between charge density




{\displaystyle \rho (\mathbf {x} )}
and current density





{\displaystyle \mathbf {J} (\mathbf {x} )}
This does not mean that individual positive and negative charges cannot be created or destroyed. Electric charge is carried by subatomic particles such as electrons and protons. Charged particles can be created and destroyed in elementary particle reactions. In particle physics, charge conservation means that in reactions that create charged particles, equal numbers of positive and negative particles are always created, keeping the net amount of charge unchanged. Similarly, when particles are destroyed, equal numbers of positive and negative charges are destroyed. This property is supported without exception by all empirical observations so far.Although conservation of charge requires that the total quantity of charge in the universe is constant, it leaves open the question of what that quantity is. Most evidence indicates that the net charge in the universe is zero; that is, there are equal quantities of positive and negative charge.

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  1. Z

    A Majorana mass term for the electron

    hi, while studying Majorana mass term can be added for the neutrino - as they are neutral - but cannot be added for the electron -as it would violate the charge conservation - i could not understand how charge conservation for Majorana mass term of electron is violated. kindly help
  2. Kostik

    A Dirac's Conservation of Matter: A Closer Look

    In Dirac's "General Theory of Relativity", at the end of Ch. 25 (p. 47), right after deriving the full Einstein equation ##R^{\mu\nu} - \frac{1}{2}g^{\mu\nu}R = -8\pi\rho v^\mu v^\nu = -8\pi T^{\mu\nu}##, he makes a reference to the conservation of mass (Eq. 25.3): $$0 = (\rho v^\mu)_{:\mu} =...
  3. Ahmed1029

    I Charge conservation and special relativity

    If conservation of charge gets violated in future experiments, what would be the implications on relativity? I have some faint idea that this will cause photons to have non-zero rest mass, but does this affect special relativity at all? Also, does special relativity make conservation of charge...
  4. T

    The back way for deriving Maxwell's Equations: from charge conservation?

    I found one article in 1993 talking about it.[Unacceptable reference deleted by the Mentors]
  5. E

    Show charge conservation in a curved spacetime

    For the flat spacetime we could just use that partial derivatives commute as well as the antisymmetry of ##F^{ab}##, i.e. ##\partial_b \partial_a F^{ab} = -\partial_b \partial_a F^{ba} = -\partial_a \partial_b F^{ba} = -\partial_b \partial_a F^{ab} \implies \partial_b \partial_a F^{ab} = - 4\pi...
  6. T

    Can the charge conservation law be derived from Maxwell equations?

    From Maxwell's equations \partial_\nu F^{\mu\nu}=J^{\mu}, one can derive charge conservation. The derivation is 0\equiv \partial_\mu \partial_\nu F^{\mu\nu}= \partial_\mu J^{\mu} { \Rightarrow}\partial_\mu J^{\mu}=0. However, a circular reasoning exists in it. For the sake of better...
  7. S

    Charge conservation on capacitor

    1. Homework Statement final charge on 3 microF be q1, on 2 microF be q2 and on 1.5 microF be q3 Intial charge on 3 microF is 360 microC and intial charge on 2 microC is 300 microF Homework Equations how the charge conservation takes place at the three junctions in the circuit The Attempt...
  8. C

    Charge Conservation in Particle Collisions

    I did a quick search through the forums and didn't find the answers I was looking for, so I thought I'd ask. Does charge conservation still apply for collisions between elementary particles? I'm taking a second year foundations of physics course, and we were given a fairly simple looking...
  9. Spinnor

    Vac fluct e+/e- field correlated because charge conservation

    Are fluctuations of the electron/positron field correlated in space and time because of charge conservation? We can't just have some positive charge just pop into existence, even if only for a moment? Thanks for any help!
  10. Clear Mind

    Is Charge Conserved in Electromagnetic Interactions Between Particles?

    Suppose you have two charged particles that interact by e.m. potential ##V(\vec{r_1},\vec{r_2})##, the total charge is conserved. Since there's a conserved quantity, it must exist a transformation for which the hamiltonian is invariant (Noether theorem). Let's be the operator ##U##...
  11. M

    Charge Conservation & Isolated Systems

    A isolated system in which number of charges present is always constant. Suppose a high energy gamma radiation enters into the isolated system and produces positron and electron (pair production), now the total number of charges present in the system increases right? Then how the charge...
  12. R

    Why doesnt neutron scattering violate charge conservation?

    p + n -> p + n + ∏^- check charge conservation: + 1 + 0 = +1 + 0 -1 it doesn't equal so it wouldn't be possible? please could someone suggest why this is, or if I'm doing something wrong? thanks in advance. edit is it because the pion is the force carrier therefore should not be...
  13. M

    Charge conservation in capacitors

    In the circuit, all elements are ideal. For time t<0, S1 remained closed and S2 open. At t=0, S1 is opened and S2 is closed. If the voltage Vc2 across the capacitor C2 at t=0 is zero, the voltage across the capacitor combination at t=0+ ?? I tried this problem. Obviously, Vc1(0) = 3V ...
  14. J

    Beta Decay Charge conservation

    Homework Statement Sorry charge conservation is not really part of the problem. Question I'm stuck on is: What is the process of decay for Be7 to Li7Homework Equations Qb+=[M(Be)-M(Li)-2Me]c2 Qb-=[M(Be)-M(Li)]c2 Qe=[M(Be)-M(li)]c2-Bn The Attempt at a Solution I know that t is not beta minus...
  15. nomadreid

    Creation of singlets: charge conservation?

    When massless particles are given mass by the Higgs mechanism, then there is no problem with charge conservation if a matter-antimatter pair is created. But what happens when a single charged particle is created? Where happens to the conservation of charge?
  16. S

    Beta Decay Charge Conservation

    Hey so, I was just wondering: If Carbon-14 (6 protons, 8 neutrons) decays into an electron, a neutrino, and Nitrogen 14 (7 protons, 7 neutrons) How is charge conserved? I get that nucleons are conserved, but if nitrogen-14 is neutral, then it has 7 protons and 7 electrons, versus Carbon...
  17. J

    Beta decay Charge conservation

    In beta decat the u quark fromthe proton and the d quark from the neutron interact to produce a electron and it's neutrino. I'm wondering about the charge conservation of this process because a neutron has zero charge and a proton has charge of 1. How do we end up with a electron charge of -1 at...
  18. H

    Charge Conservation in Plasma Physics

    I have been working with someone on plasma physics. We have a simple model of a laser hitting a charge neutral plasma. The laser promotes the electrons in the plasma into a high energy electron beam. We have been looking at the problem in 1D using the Lorentz force law, the conservation of...
  19. K

    Local vs. global charge conservation

    Is it correct that theories such as the free complex scalar field or the free Dircac field with their global U(1) symmetry give rise to only globally conserved charges (a globally conserved Noether charge)? If so, how can that be shown? Also, is it somewhat correct to say that the main reason...
  20. I

    Charge Conservation: Exploring the Conservation Law

    I've been thinking about this for a while, my personal example was a nuclear explosion, but I'm talking in general about events in which matter is converted to energy.. Sticking to my original string of thought, in a nuclear detonation, matter is transformed into energy. But matter consists of...
  21. P

    Charge conservation in curved spacetime

    I'm reading some texts on general relativity and I am wondering how one can mathematically proof that the covariant derivative (wrt mu) of the four-vector j^mu equals zero. I know that the covarient derivative (wrt nu) of F^mu^nu equals the four-current times some costant and that you should...
  22. S

    Biot-Savart + Coulomb + Charge Conservation = Maxwell?

    Biot-Savart + Coulomb + Charge Conservation = Maxwell?? Do the Biot-Savart Law, Coulomb's Law, and the Law of Charge Conservation contain the same information as Maxwell's Equations? i.e. \begin{cases} d\vec{B} = \frac{\mu_o}{4\pi} \frac{I d\vec{l} \times \hat r }{r^2} \\ \vec{E}=...
  23. W

    Is Charge Conservation Violated in Spherical Volumes with Zero Current Density?

    hi, guys: Charge conservation Violated? It seems to be: The charge density inside a spherical volume changes from \rho at t=0, after period of time \tau , the charge density decrease to 0. However, the author claimed that during the processing there is no current density in the material...
  24. K

    Charge Conservation in Neutron Decay

    A neutron can decay into a proton, a positron, and a neutrino. A proton is made up of two up quarks and a down quark. A neutron is made up of one up quark and two down quarks. An up quark has a charge of +2/3, and a down quark has a charge of -1/3. Given the statements above, can someone...
  25. F

    Where can I find the proof for charge conservation?

    Hi, does anyone know where I can find the proof for charge conservation, or another way to prove this. The problem states: Prove that whenever I charge a sphere and touch another uncharged sphere, the charges are distributed between them evenly.
  26. C

    Charge Conservation: Understanding Klein-Gordon Equation

    So, I was just introduced to the Klein-Gordon equation. I've been asked to derive the continuity equation for charge density and current density. I am having trouble understanding this. If I were to derive a continuity equation involving charge, doesn't this say that charge is conserved...