In a DC circuit, a capacitor will charge to the voltage of the source.

• A. It will act as a short circuit
• B. It will discharge completely
• C. It will charge to the source voltage
• D. It will prevent any current flow

Answer: (C)

The key idea is what happens to a capacitor in a DC circuit as it reaches steady state. When a DC source is connected, the capacitor starts charging, and the current is initially present because the capacitor looks like a very small impedance. As charge builds up on the plates, the voltage across the capacitor rises, which reduces the current. This continues until the voltage across the capacitor equals the source voltage. At that point, the current effectively stops in an ideal circuit, and the capacitor holds the source voltage. So the final state is that the capacitor charges to the source voltage. It isn’t a permanent short, nor does it discharge on its own without a path to remove charge, and it doesn’t permanently prevent all current flow during the charging process.