What happens to capacitive reactance when the frequency of the applied voltage increases?

Capacitive reactance is the opposition that a capacitor presents to the flow of alternating current (AC), and it is inversely related to both the frequency of the applied voltage and the capacitance. The formula for capacitive reactance (Xc) is given by:

[ Xc = \frac{1}{2 \pi f C} ]

where:

• ( f ) is the frequency of the applied voltage,

• ( C ) is the capacitance in farads.

As the frequency (( f )) increases, the value of ( 2 \pi f C ) in the denominator becomes larger, resulting in a smaller overall value for ( Xc ). This means that as the frequency increases, the capacitive reactance decreases.

This relationship is crucial in AC circuits, as it explains how capacitors behave when the frequency of the voltage applied to them changes. In practical terms, when the frequency increases, capacitors allow more current to pass through them, as they present less opposition to the current flow.