AC and DC in a charging system
Sorry if this is in the wrong forum, I was hoping that somebody could offer some guidance on a task I've been set. I've been asked to "discuss the principals of alternating current and direct current in a charging system". To me the question is very vague, so I'm assuming they mean a circuit with a capacitor to store charge.
In DC, I understand the current flows in one direction, and as the capacitor charges to the DC value of the source, the current flow and charge decrease and increase respectively exponentially until the capacitor is fully charged and the current flow is zero. Hence why capacitors appear to block DC. The capacitor then holds the charge until the source is removed.
However I'm struggling with AC. Am I right in saying that as the current flows in one direction then another, the capacitor charges and discharges with alternating polarity? Could somebody please elaborate on how a capacitor behaves in AC please?
Thank you in advance, I appreciate any help on this.