A charged capacitor is connected in series with a resistor and an open switch. At time t = 0 s, the switch is closed. Which of the graphs below best describes the potential difference V across the resistor as a function of time t?

Question

Quizplus · Accepted Answer

- Initially, when the switch is closed, the capacitor is fully charged and acts as a voltage source, while the resistor acts as a load. Therefore, the potential difference across the resistor will initially be equal to the voltage across the capacitor.
- As time passes, the capacitor will start to discharge through the resistor, resulting in a decrease in the potential difference across the resistor. The rate of decrease will be dictated by the time constant RC, where R is the resistance and C is the capacitance of the circuit. 
- The potential difference across the resistor will eventually reach zero once the capacitor is fully discharged, which will take approximately 5 time constants. Therefore, the graph that best represents this scenario is option B.

A Charged Capacitor Is Connected in Series with a Resistor