# Does resistance increase as voltage increases?

I'm assuming the answer would be yes? Because as voltage increases, electrons move faster and then make more and more collisions with the lattice? could someone confirm this please.

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By increasing V on a certain R you increase I and then joule losses P = R*I^2 or P = R*(V/R)^2 = V^2/R

All this leads to a higher temperature T and since resistivity ρ ≡ T , then the resistance will increase : how much ?

It depends upon the material : talking about copper ,the relevant equation is :

Rx = Ro(234+Tx)/(234+To)

if To = 20°C and Tx = 120°, then Rx = Ro*1.394 which means and increment close to 40%

• Temperature causes expansion of the cross section area of the conductor.power is the product of voltage and velocity

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• Anonymous
1 year ago

Rx = Ro(234+Tx)/(234+To)

if To = 20°C and Tx = 120°, then Rx = Ro*1.394 which means and increment close to 40%

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• No, look back at the Ohms law

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• Anonymous
1 year ago

Yes.

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• No. Resistance remains the same. Current flow can change due to frequency according to the math.

That's usually known as impedence.

Resistance and impedence are similar but not exactly the same.

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• It depends on the material. In a "resistor", ideally the resistance is constant under all conditions (and probably changes a little with temperature). A Zeiner diode is constructed so that, in the back current direction, the resistance does increase with voltage.

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• it depends

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• It depends on the circuit. In some non linear loads the Resistance does change. but if it is a linear load R is a fixed quantity and as Voltage increases so does current.

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• In basic Physics problems, treat resistance as a constant. What oubaas and steveforphysics said is correct. And your comment s under the answer by oubaas are correct. If the current in a wire is so high that the heat from I^2R cannot radiate away fast enough to prevent the temperature increasing, then the resistance would increase. But that is a side-effect of the voltage increasing. It also means that wire should be a thicker gauge for safety. Unless this is intentional, like in a lightbulb or heater

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• yes. This is true. When you increase voltage, the resistance increases and heats more. When current passes through the wire, it heats up. More the current leads to more heating. Since current is proportional to the voltage, the resistance increases. This happens in bulbs which use Tungsten wire.

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