In a power supply capacitive filter, the capacitor is indeed connected in parallel with the load. This configuration is essential because it allows the capacitor to smooth out the voltage supplied to the load by reducing ripple voltage, which is the variation in voltage that occurs when converting AC to DC.
When the capacitor is placed in parallel, it charges up when the voltage from the rectifier is higher than the voltage across the load. Then, when the voltage drops below that level, the capacitor discharges its stored energy back into the load. This process helps maintain a more stable DC voltage by bridging gaps in the voltage supply, thereby providing a less fluctuating power source for the connected load.
Placing the capacitor in series with the load would not be effective in this context, as it would block the direct current that the load requires, making it ineffective for smoothing purposes. Therefore, the parallel configuration is the correct approach for a capacitive filter in power supply applications.