RC Circuit

R W C mF
In this simulation, a resistor and a capacitor are connected in series to a 12-Volt battery. When the switch closes, the capacitor begins to charge. A voltmeter is connected across the capacitor, and a graph of the voltage across the capacitor vs. time is also shown. Vary the values of the resistor (1 W < R < 10 W) and capacitor (10 mf < C < 50 mf). How do these affect the charging of the capacitor?


  1. As you increase or decrease R or C, how long does it take for the voltage on the capacitor to approach its maximum value?
  2. What is the maximum voltage attained? Why?
  3. How does the voltage on the capacitor reflect the amount of charge placed on the capacitor?


See Serway and Beichner, Physics For Scientists and Engineers 5th Edition, Section 28.4

Illustration written by Steve Mellema and Chuck Niederriter