it states that the voltage across an inductor is V = L(di/dt), why do we not use V = IR? Or what is the derivation of V = L(di/dt) or the conceptual explanation?
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Ohms law is about DC system whre you have a steady state. That is the common ohms law with just real variables.
If you have AC system you need to include capacitive and inductive effects. The result of them it that the change of voltage is not in contact with the whole system and that the current is not identical in all of the wires.
If you instead of resistance use impedance Z, that is a way to describe both resitive, capacitive and capacitive effects you can still use ohwm law.
The variable is then a complex number.
For an inductacne the impedance is Z = jwL where j is used instead of I for the imaginary unit. w is the frequency and L is the inductance.
V = I * Z = I* JwL
That is the equation you can use for an inductance. It is relatively simple for just a sine wave when w is a single frequncy.
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