Capacitive Reactance Formula

A capacitor is a device used to store electrical energy. The capacitance of a capacitor determines the amount of charging a capacitor can achieve. The measure of the opposition to alternating current by the capacitor is called Capacitive Reactance. The unit of Capacitive Reactance is Ohms like resistance. The symbol of Capacitive Reactance is X_C .

Capacitive Reactance Formula is expressed by

Where in,

X_C  is the capacitance reactance measured in ohms

C = capacitance in farads

f = frequency in hertz

Solved Examples

Example 1

Calculate the capacitive reactance if 40 mF is connected to a frequency generator of 50 Hz signal.

Solution

According to given parameters

C= 40 mF

F = 50Hz

The capacitance reactance formula is given by

Xc = 1 / 2πfC

= 1 / 2×3.14× 40×10⁻³×50

= 0.07961Ω

Example 2

Calculate the reactance of capacitance in an AC circuit wherein the input signal has a frequency of 100 Hz and a capacitor has a capacitance of 1000mF in a circuit.

Solution

Given

F = 100 Hz

C = 1000 mF

The capacitance reactance formula is given by

xc = 1 / 2πfc

xc = 1 / 2 x 3.14  x 100 x 1000 x 10^-3

= 1.5  x 10^-3 Ω

Hence, the capacitive reactance is 1.5 x 10^-3Ω