Voltage & Resistance Experiment: Can Resistance Change?

In summary, the conversation discusses an experiment on insulating coating on a powder and measuring resistance with various voltages. Despite Ohm's law stating that resistance should be constant, the sample showed different resistance at different voltages. The possibility of resistance changing and the effects of temperature on the experiment are also mentioned. Further clarification and raw data are requested.
  • #1
sunwoo lee
2
0
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...
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
Can you post your raw data? V, i, R?
 
  • #3
It is possible. Take a look a the IV curve for a diode. At different voltages the slope of the curve changes.
 
  • #4
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.
 
  • #5
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.
 
  • #6
The temperature should be constant. I did not clearly understand your experiment, more detail please ?
 

1. What is resistance?

Resistance is a measure of how much a material or component opposes the flow of current in an electrical circuit. It is measured in ohms (Ω) and is represented by the symbol R.

2. How is resistance related to voltage?

Ohm's law states that the current in a circuit is directly proportional to the voltage and inversely proportional to the resistance. This means that as the voltage increases, the resistance will decrease, allowing more current to flow through the circuit.

3. Can resistance change in a circuit?

Yes, resistance can change in a circuit depending on various factors such as temperature, material, and length of the circuit. For example, as the temperature of a material increases, its resistance also increases.

4. How can we measure resistance?

Resistance can be measured using a multimeter, which is a device that measures voltage, current, and resistance. It can be connected to different points in a circuit to measure the resistance between those points.

5. What is the purpose of conducting a voltage and resistance experiment?

The purpose of conducting a voltage and resistance experiment is to understand the relationship between these two electrical properties and how they affect the flow of current in a circuit. This experiment can also help to determine the resistance of a particular material or component and how it may change under different conditions.

Similar threads

I Resistance and specific resistance relationships
    • Electromagnetism
Replies
16
Views
632
Is there a relationship between voltage and resistance?
    • Electromagnetism
Replies
6
Views
2K
Putting internal resistance in series with a voltage source
    • Electromagnetism
Replies
10
Views
995
Is Current in Superconductors Truly Infinite?
    • Electromagnetism
Replies
9
Views
1K
Resistance of wet sponge with voltage
    • Electrical Engineering
Replies
10
Views
1K
Electricity, voltage, current, resistance relationship
    • Electromagnetism
Replies
23
Views
2K
I Quantum Hall Effect and Hall Voltage
    • Quantum Physics
Replies
0
Views
90
I What happens to resistance of tap water as voltage is increased?
    • Classical Physics
Replies
22
Views
2K
Resistance of a bulb 100 W, 230 V
    • Electromagnetism
Replies
16
Views
6K
Current: the speed of charges vs the number of charges past a point
    • Electromagnetism
2
Replies
37
Views
2K

Hot Threads

Recent Insights

Back
Top