What letter is used to represent reactance?

In standard electrical engineering notation, the letter X is assigned to represent reactance. You will typically see it written with subscripts, such as X_C for capacitive reactance or X_L for inductive reactance. It is important to clearly differentiate the various letters used in AC circuit analysis. The letter Z is reserved for total impedance, which mathematically combines both resistance (R) and reactance (X). The other distractors, Y and B, represent admittance and susceptance respectively. These are the mathematical reciprocals of total impedance and reactance.