Trivia 3 ~ Answer 1 – Capacitive Reactance

A Capacitor is a passive component that has the ability to store energy in the form of potential differences between its plates. It resists a sudden change in voltage. The charge is stored in the form of potential difference between two plates, which form to be positive and negative depending upon the direction of charge storage. Initially, the negative and positive charges on two plates of the capacitor are in equilibrium.

There is no tendency for a capacitor to get charged or discharged. The negative charge is formed by the accumulation of electrons, while the positive charge is formed by the depletion of electrons. As this happens without any external charge given, this state is an electrostatic condition. When an external voltage is given, the electric charge gets converted into an electrostatic charge. This happens while the capacitor is charging.

The positive potential of the supply, attracts the electrons from the positive plate of the capacitor, making it more positive. While the negative potential of the supply, forces the electrons to the negative plate of the capacitor, making it more negative.

Capacitive Reactance is the opposition offered by a capacitor to the alternating current flow, or simply AC current. A capacitor resists the change in the flow of current and hence it shows some opposition which can be termed reactance, as the frequency of the input current should also be considered along with the resistance it offers. Symbol: XC In a purely capacitive circuit, the current IC leads the applied voltage by 90°. Capacitive reactance is measured in ohms of reactance like resistance and depends on the frequency of the applied voltage and the value of the capacitor.

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