summary
● When an AC voltage is applied to a capacitor, it gives the appearance of current flow.
● The capacitor charging and discharging represents current flow.
● The current leads the applied voltage by 90° in a capacitive circuit.
● Capacitive reactance is the opposition a capacitor offers to the applied voltage.
● XC represents capacitive reactance.
● Capacitive reactance is measured in ohms.
● Capacitive reactance can be calculated by the formula:
● RC networks are used for filtering, coupling, and phase shifting.
● A filter is a circuit that discriminates against cer- tain frequencies.
● A low-pass filter passes frequencies below a cutoff frequency. It consists of a resistor and capacitor in series.
● A high-pass filter passes frequencies above a cutoff frequency. It consists of a capacitor and resistor in series.
● Coupling networks pass AC signals but block DC signals.