Potential Difference between two points in battery

AI Thread Summary
A battery with an electromotive potential (EMP) of 12V and an internal resistance of 2 ohms exhibits different terminal-to-terminal potential differences based on current direction. When current flows from the negative to the positive terminal, the potential difference is less than 12V due to internal resistance. Conversely, when current flows from the positive to the negative terminal, the potential difference can exceed 12V, as an external force may be pushing current against the battery's normal direction. If there is no current, the terminal voltage equals the EMP of 12V. Understanding these concepts clarifies how internal resistance affects voltage readings in various scenarios.
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
 
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oh i was doing the loop rule by accident. that's why i was setting them equal to zero.
 
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