Potential Difference between two points in battery

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SUMMARY

The discussion centers on the potential difference across a battery with an electromotive force (EMF) of 12V and an internal resistance of 2 ohms. It concludes that the terminal-to-terminal potential difference varies based on the direction of current flow: when current flows from the positive to negative terminal (b), the potential difference exceeds 12V due to external influences, such as a higher voltage source. In contrast, when current flows from negative to positive (a), the potential difference is less than 12V, and when there is no current (c), it equals 12V.

PREREQUISITES
  • Understanding of electromotive force (EMF)
  • Knowledge of internal resistance in batteries
  • Familiarity with Ohm's Law
  • Basic concepts of electric current direction
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  • Explore the effects of external voltage sources on battery behavior
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mb85
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more so help with the concept than anything else.

A battery has an EMP of 12v and an internal resistance of 2 ohms. Is the terminal-to-terminal potential difference greater than, less than, or equal to 12v if the current in the battery is from a) from the neg to pos. terminal b) from pos to neg terminal c) zero?

I realize that you loose potential in going from a neg. to pos. terminal.
so for:
a) +E -iR = 0
b) -E + iR = 0
c) they are equal.

im just a little foggy on why b is greater than 12V.
thanks in advance!
 
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mb85 said:
more so help with the concept than anything else.

A battery has an EMP of 12v and an internal resistance of 2 ohms. Is the terminal-to-terminal potential difference greater than, less than, or equal to 12v if the current in the battery is from a) from the neg to pos. terminal b) from pos to neg terminal c) zero?

I realize that you loose potential in going from a neg. to pos. terminal.
so for:
a) +E -iR = 0
b) -E + iR = 0
c) they are equal.

im just a little foggy on why b is greater than 12V.
thanks in advance!
If E and i are positive, b) should be E + iR and neither a) nor b) should be set = 0. These are the terminal voltages. They are not zero.

In b), something out there (perhaps a higher voltage battery, or a battery charger) is forcing current "backwards" through the battery
 
Last edited:
oh i was doing the loop rule by accident. that's why i was setting them equal to zero.
 

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