When voltage is applied to a capacitor, what happens initially?

When voltage is applied to a capacitor, the initial behavior involves the current flowing into the capacitor. At the moment voltage is first applied, the capacitor is uncharged and acts like a short circuit, allowing maximum current to flow into it. As the capacitor begins to charge, the voltage across it increases, which causes the current to start decreasing. This behavior follows the exponential charging curve characteristic of capacitors in a circuit. Initially, the current is indeed at its maximum value because the capacitor is initially at zero volts—meaning there is a significant potential difference driving current flow. As the capacitor continues to charge, its voltage approaches that of the source, leading to a reduction in the current until it eventually reaches a steady state where the current drops significantly, ideally approaching zero.

Other options do not capture this behavior accurately. While current does eventually reduce to zero as the capacitor reaches full charge, it does not drop instantly, and it does not remain constant throughout the charging process either. The notion that current flows only in one direction is not unique to capacitors—it is characteristic of DC circuits in general, and does not specifically address the charging process of capacitors.