Current through resistor, with heat. What happens to the current?

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Homework Help Overview

The discussion revolves around the behavior of current flowing through a resistor as it heats up, specifically whether the current will increase, decrease, or remain constant under the assumption of constant voltage.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants explore the relationship between temperature and resistance, with some suggesting that increased resistance due to heating will lead to a decrease in current. Others question the assumptions regarding the nature of the resistor and its resistance characteristics.

Discussion Status

The discussion includes varying perspectives on the effect of temperature on resistance and current. Some participants are considering the implications of an ideal resistor versus a real resistor made of wire, leading to a productive exploration of the topic without reaching a consensus.

Contextual Notes

Participants are operating under the assumption that the voltage across the resistor remains constant, which influences their reasoning about current behavior in response to temperature changes.

rcmango
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Homework Statement



Suppose a current of 1 A is flowing through a resistor. If this makes the resistor heat up, will the current through the resistor increase, decrease, or remain constant? Assume the voltage applied to the resistor is constant.

Homework Equations





The Attempt at a Solution



Please help me with this, I'm not sure, but I believe the current will decrease slightly because of the heat dissipated?
 
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rcmango said:

Homework Statement



Suppose a current of 1 A is flowing through a resistor. If this makes the resistor heat up, will the current through the resistor increase, decrease, or remain constant? Assume the voltage applied to the resistor is constant.

Homework Equations





The Attempt at a Solution



Please help me with this, I'm not sure, but I believe the current will decrease slightly because of the heat dissipated?

The resistance of many electrical components changes with temperature. Certainly the resistance of a wire increases when it gets hotter, so if the resistor is actually made up of a length of wire you can expect that change in resistance - with an effect on the current I am sure you can predict.
 
Okay, so as the wire heats up the resistance of the wire increases, this causes the current to decrease. Is that correct?
 
rcmango said:
Okay, so as the wire heats up the resistance of the wire increases, this causes the current to decrease. Is that correct?

That sounds good.

EDIT: provided the resistor is made using wire.
 
Last edited:
The current decrease is NOT because of the heat dissipated. For an ideal resistor that does not change resistance even if it heats up, the current doesn't change.
 

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