Christophe wrote:Arf trap question!
For me the joule effect is the opposite: creation of heat by the circulation of an electric current.
Yes
Obviously the more resistance there is, therefore of T °, the more there is joule power ... it's a vicious circle
All false.
U = R * I, P = R * I², P = U² / R, P = UI: these are all the relationships between voltage U, current I, resistance R and power P.
What we have constant and imposed is the tension. The simplest is therefore to use P = U² / R:
the more the resistance increases, the more the power decreases.
It is all the more obvious that a very high resistance is like an open circuit, therefore little or no power, and that a low resistance is like a short circuit, therefore theoretically infinite power which will cause the short to burn out. -circuit or jump the circuit breaker.
So when we light a filament lamp, there is a pulse overcurrent at the start, then the resistance increases because of the heat, so the current decreases and stabilizes at the value I = U / R where R is the resistance at nominal operating temperature.