As noted above, capacitors and inductors are basically functional opposites of each other. Therefore, it should be no surprise that in some circuits their effects tend to cancel each other. In other circuits their effects will tend to build upon each other.

Inductors and capacitors in series.

If an inductor and capacitor are wired in series, the inductive reactance and capacitive reactance will cancel each other. By convention, to calculate total reactance you subtract capacitive reactance from inductive reactance. This will give you a positive number if more inductive reactance remains and a negative number if more capacitive reactance remains.


Where:

	X	=	Total reactance
	XL	=	Inductive reactance in ohms
	XC	=	Capacitive reactance in ohms

If you have a capacitive reactance of 75 ohms and an inductive reactance of 50 ohms, the total reactance is 25 ohms of capacitive reactance or -25 ohms.

50 – 75 = –25.

Since the result is a negative number, the circuit is capacitive.

We will get deeper into inductive-capacitive circuits a bit later. First let's review some math.