A capacitor with capacitance C is initially uncharged and connected in series with a resistor of resistance R and a battery of voltage V. After a long time, what is the voltage across the capacitor?

Core Concept

In an RC circuit, after a long time (theoretically infinite time), the capacitor becomes fully charged and acts like an open circuit. The voltage across the capacitor equals the battery voltage V, as there is no current flowing through the resistor (IR = 0), so the voltage drop across the resistor is zero.