Calculating Inductance

Thread Starter


Joined Apr 7, 2006
Ive been using complex numbers and my scientific calculator to great
success as shown in this sites tutorial. I like the why I can just use ohms law, as with DC analysis.

But how do I calculate the inductance without going back to trig.

Parallel R-L ac circuit:
"Resistor 40R;
Supply 200V, 50Hz
Supply current is 8A.
Inductor, L?

Whats the inductance of the coil, L?"


Joined Apr 20, 2004

No Trig, just simple algebra.

I = E/R, using the 40 ohm resistor, will give you something other than 8 amps. R = E/I will give you the resistance of the paralleled resitor and inductance. Figure the correct resistance to parallel with 40 ohms that give the 8 amps of current. Then, using L = RL/2piF, you have the inductance.