I have a school exercise that goes like this:
Voltage is 230V. Frequency is 50Hz. Inductor is 400mH.
How big of a resistor should be added with the inductor (in a series) to reduce reactive power by 75%? (The correct answer is apparently 218 ohms.)
How do you calculate this? Is this even possible? I know only of capacitors reducing reactive power.
I can only figure out that 25% of the reactive power is be 105,24 var. Also sorry, I don't study in English, so the terms might be a bit strange. Thank you.