To eliminate the pulsating output voltage in a circuit, which component should be added?

To eliminate the pulsating output voltage in a circuit, the addition of a capacitor is beneficial because capacitors are designed to store and release electrical energy, which helps smooth out voltage fluctuations. When connected across the output of a circuit, a capacitor can charge when the voltage rises and discharge when the voltage drops. This action effectively reduces the variations in voltage, resulting in a more stable output.

In applications like power supply circuits, especially those that convert alternating current (AC) to direct current (DC), capacitors serve as filters. They absorb peaks in voltage and fill in dips, thereby transforming a pulsating DC output into a smoother and more constant voltage level. The capacitance value and specific circuit design determine how well the capacitor can accomplish this task.

Other components may play different roles in a circuit, but they do not fulfill the same function as effectively as a capacitor for this specific purpose. Inductors and resistors would influence current flow and voltage drop, while transformers are primarily used for voltage transformation rather than smoothing voltage fluctuations directly.