Voltage & Resistance Experiment: Can Resistance Change?

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    Resistance Voltage
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Discussion Overview

The discussion revolves around an experiment measuring resistance in a sample with insulating coating at various voltages. Participants explore whether resistance can change under different voltage conditions, referencing Ohm's law and the behavior of materials under varying electrical conditions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant notes that their experiment showed varying resistance with different voltages, challenging the assumption of constant resistance as per Ohm's law.
  • Another participant requests raw data from the experiment to better understand the findings.
  • Some participants propose that resistance can change, citing the IV curve of a diode where the slope varies with voltage.
  • It is mentioned that even simple wires can exhibit non-linear behavior at higher currents and voltages due to heating effects, which may lead to deviations from Ohm's law.
  • One participant emphasizes that Ohm's law assumes constant temperature, suggesting that confusion arises between the law and the formula for resistance.
  • A request for more details about the experiment is made, indicating a need for clarification on the conditions under which the measurements were taken.

Areas of Agreement / Disagreement

Participants express differing views on whether resistance can change with voltage, with some supporting the idea and others seeking clarification on experimental conditions. The discussion remains unresolved regarding the implications of the findings.

Contextual Notes

Participants note the importance of temperature control in experiments involving resistance and the potential for non-linear behavior in materials under varying electrical conditions. Specific assumptions about the experimental setup are not fully detailed.

sunwoo lee
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recently, I did a experiment about insulating coating on a powder.

and I measured resistance with various voltage.

according to Ohm's law, the resistance is constant

however, my sample showed different resistance with difference V.

At every voltage, I checked the currents and the resistance and their multiplies(I*R) show same voltages.

Is it possible that resistance changes?

Please, explain me if anyone can...
 
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Can you post your raw data? V, i, R?
 
It is possible. Take a look a the IV curve for a diode. At different voltages the slope of the curve changes.
 
Even for a simple wire, Ohm's law won't always hold. As you increase the current and voltage, at some point the I-V curve will become non-linear due to the wire heating up.
 
Vagn said:
Even for a simple wire, Ohm's law won't always hold. As you increase the current and voltage, at some point the I-V curve will become non-linear due to the wire heating up.
Ohm's law actually stipulates constant temperature. People confuse Ohm's Law with the simple formula for Resistance (=V/I). There is a distinct difference, of course.
 
The temperature should be constant. I did not clearly understand your experiment, more detail please ?
 

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