Define capacitive reactance. Write its SI unit.

Capacitive reactance is a term used in electrical engineering and physics to describe the opposition that a capacitor presents to alternating current (AC). It is denoted by the symbol XC and is measured in ohms (Ω).

The capacitive reactance (XC) of a capacitor is inversely proportional to the frequency (f) of the alternating current passing through it and the capacitance (C) of the capacitor. It can be calculated using the following formula:

XC = 1 / (2πfC)

Where:
XC is the capacitive reactance in ohms (Ω)
π is a mathematical constant (approximately 3.14159)
f is the frequency of the alternating current in hertz (Hz)
C is the capacitance of the capacitor in farads (F)

The SI unit of capacitive reactance is ohms (Ω), which is the same as the unit of resistance.