When a battery will no longer produce current

  • Thread starter Thread starter John Galt
  • Start date Start date
  • Tags Tags
    Battery Current
AI Thread Summary
When a battery no longer produces current, it does not mean that the positive and negative terminals have equal charge; instead, it indicates that the electric potential difference has diminished. Current flows due to a difference in electric potential, and when this potential equalizes, current ceases. Even when a battery is considered "dead," it still contains charge that cannot be utilized because the chemical reactions necessary for electron flow have completed. Connecting the terminals to a new grounded reservoir would not generate current, as the battery's internal RedOx reactions are exhausted. Ultimately, a battery functions by facilitating electron movement through a circuit, and once that process is finished, it cannot provide further energy.
John Galt
Messages
15
Reaction score
0
When a battery will no longer produce current does this mean the negative and positive terminals have equal charge? Current flows from the negative to the positive based on there being a higher and a lower electric potential between the poles, so when the current stops flowing is it because these two poles have reached equilibrium?
 
Physics news on Phys.org
I think the electric potential of the poles are equal as there are no current produced
 
Well, if that's true, there is still charge left in a battery when it won't work anymore because it has nowhere to go. What if both poles of a spent battery were wired to a new grounded reservoir? Would current flow?
 
A battery isn't like a tank full of electrons. It has no net charge and only works by pushing electrons around a loop.
 
A chemical reaction is allowed to occur by connecting the leads of a battery. Inside, a Reduction-Oxidation ("RedOx") reaction occurs in which electrons are transferred from one substance to anther (through your circuit). When the battery is "dead", the reaction is complete and no further work can be extracted out of the system.
 
This is from Griffiths' Electrodynamics, 3rd edition, page 352. I am trying to calculate the divergence of the Maxwell stress tensor. The tensor is given as ##T_{ij} =\epsilon_0 (E_iE_j-\frac 1 2 \delta_{ij} E^2)+\frac 1 {\mu_0}(B_iB_j-\frac 1 2 \delta_{ij} B^2)##. To make things easier, I just want to focus on the part with the electrical field, i.e. I want to find the divergence of ##E_{ij}=E_iE_j-\frac 1 2 \delta_{ij}E^2##. In matrix form, this tensor should look like this...
Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'
Please can anyone either:- (1) point me to a derivation of the perpendicular force (Fy) between two very long parallel wires carrying steady currents utilising the formula of Gauss for the force F along the line r between 2 charges? Or alternatively (2) point out where I have gone wrong in my method? I am having problems with calculating the direction and magnitude of the force as expected from modern (Biot-Savart-Maxwell-Lorentz) formula. Here is my method and results so far:- This...
Back
Top