Question 11: A capacitor is connected in series with a resistor and charged. Explain why the potential difference across the resistor decreases with time during charging?

ANSWER

A circuit in which a resistor and a capacitor are connected in series is technically called an R-C circuit. Let the battery is connected to charge the plates of the capacitor via electric resistor. Initially, charging of the uncharged plates takes place rapidly. However, as the time passes, charge accumulates on the plates of the capacitor. This slowly decreases the flow of charge (current) through the circuit. By Ohm’s law, we know that V = IR. Where I is the current through the circuit and R is the resistance of the resistor. As R is constant, so when I (flow of charge through the circuit) decreases with time due to the accumulation of charge on the plates of the capacitor, V also decreases in the same way. Therefore, in an R-C circuit, the potential difference across the ends of the resistor decreases with time.