The discussion revolves around finding the voltage across resistors in an RL circuit, specifically addressing the behavior of inductors and their impact on voltage and power calculations.
Participants are actively questioning assumptions about voltage drops and power in the circuit. Some guidance has been offered regarding the behavior of inductors and the conditions under which they can be treated as having zero resistance, but no consensus has been reached on the implications for power supplied by the current source.
There is an ongoing discussion about the definitions of resistance and reactance, as well as the implications of zero voltage drop across the inductor on power calculations. Participants are navigating through potential misunderstandings related to the equations used for power and voltage in the circuit.
You state that the current through the resistor is zero. Then what is the voltage drop across the resistor?Marcin H said:
0 volts right? Did I flip those 2 things? I thought inductors after a long time act like wires with no resistance. Is that not true?SammyS said:
Yes. zero.Marcin H said:
Ahhh. Ok that makes sense. But then how can we find how much power the current source would supply. P = IV = I^2R = V^2/R. Would we have to discharge the inductor and then use V=IR = (1A)(1000ohms)=1000V?SammyS said:
How do get 1000 ?Marcin H said:
Woops. I used the wrong equation. I meant to use P = I^2R = (1A)^2*(1000ohms) = 1000V. But is that wrong?SammyS said:
How would I get the resistance of the inductor? Are you talking about the reactance? Xl=wL? And isn't the voltage drop across the inductor 0? I'm not sure how that helps us find the power that the current source is supplying.
Yes, voltage drop across the inductor is indeed zero. Therefore, V⋅I = ?Marcin H said:
Power is 0? How can the power be 0? Does that mean the current source is just off?SammyS said:
no.Marcin H said: