Negative Voltage: Understanding How Current Travels

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Discussion Overview

The discussion revolves around the concept of negative voltage, particularly in the context of the Millikan Oil Drop Experiment. Participants explore the implications of negative voltage on the direction of current flow, questioning conventional understanding and definitions.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant queries whether negative voltage implies that current flows from negative to positive, challenging conventional current flow from positive to negative.
  • Another participant asserts that conventional current always flows from higher potential to lower potential, suggesting that negative voltage does not change this convention.
  • A different viewpoint suggests that if the negative terminal represents ground or reference, the positive terminal can have any potential difference, potentially leading to current flowing from the negative terminal to the positive terminal under certain conditions.
  • A later reply acknowledges that the initial agreement on the direction of current flow was misleading and clarifies the reasoning behind the assertion.

Areas of Agreement / Disagreement

Participants express differing views on the implications of negative voltage for current flow, with no consensus reached on the correct interpretation of how current behaves in this context.

Contextual Notes

The discussion highlights the dependence on definitions of voltage and potential, as well as the assumptions regarding reference points in electrical circuits.

gbaby370
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I just completed a problem regarding a Millikan Oil Drop Experiment. I ended up with a negative voltage in the solution.

I am just trying to understand negative voltage. Does it mean that the current will travel from - to + instead of the conventional + to -?
 
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gbaby370 said:
I just completed a problem regarding a Millikan Oil Drop Experiment. I ended up with a negative voltage in the solution.

I am just trying to understand negative voltage. Does it mean that the current will travel from - to + instead of the conventional + to -?

yes it does
 
phinds said:
yes it does

Umm.. I don't think so. Why would it do that? Conventionally signed current will always flow from the higher (more +ve) potential to the lower.
 
If the "-" represents the ground or reference then I believe the "+" can have any potential difference whether positive or negative. In such a case though the "-" terminal will have the higher potential and so conventional current will run from it to the "+" terminal.
 
Waterfox said:
If the "-" represents the ground or reference then I believe the "+" can have any potential difference whether positive or negative. In such a case though the "-" terminal will have the higher potential and so conventional current will run from it to the "+" terminal.

Yeah, that's what I meant, but my simple "yes" was a bit misleading, as haruspex correctly pointed out.
 

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