Voltage & Resistance Experiment: Can Resistance Change?

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The experiment revealed that resistance varied with different voltage levels, contradicting Ohm's law, which states resistance should remain constant under stable conditions. Participants noted that the I-V curve for components like diodes can show non-linear behavior at varying voltages, indicating that resistance can change due to factors like temperature. It was emphasized that Ohm's law assumes constant temperature, and deviations can occur when components heat up. Clarification on the experimental setup and raw data was requested to better understand the findings. The discussion highlights the complexities of resistance in real-world applications beyond ideal conditions.
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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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