AC Voltage Applied to a Capacitor: When an AC voltage is applied to a capacitor, the capacitor charges and discharges at the same frequency as the AC voltage. However, the phase relationship between the voltage and current in the capacitor is different than that of a resistor or an inductor.

AC Voltage Applied to a Capacitor

Initially, when the AC voltage is applied to the capacitor, the voltage across the capacitor is zero, and the capacitor behaves like a short circuit, allowing a large current to flow. As the capacitor charges, the voltage across it increases, and the current decreases. When the voltage across the capacitor reaches its maximum value, the current reaches its minimum value.

As the AC voltage begins to decrease, the voltage across the capacitor also starts to decrease, and the capacitor starts to discharge. The discharge current flows in the opposite direction to the charging current, and it is initially high, but it decreases as the voltage across the capacitor decreases. When the AC voltage reaches zero, the voltage across the capacitor reaches its minimum value, and the current is again at its maximum.

As the AC voltage starts to increase in the opposite direction, the capacitor starts to charge in the opposite direction, and the process repeats. The resulting current waveform in the capacitor leads the voltage waveform by 90 degrees.

The behavior of a capacitor in an AC circuit is important in many applications, such as in power supply filters, tuning circuits, and signal coupling. By using phasor analysis, the voltage and current waveforms in AC circuits containing capacitors can be analyzed and calculated, making it possible to predict the behavior of the circuit and design components for optimal performance.

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By Team Learning Mantras