1. RC Circuits

2. We can use a resistor to slow the charging of the capacitor. -Current now varies with time. -In the very short term, you can treat the capacitor like a wire. R = 0 -In the long term, you can treat the capacitor like a break. R = Infinite Charge on capacitor varies with time: q = q o [1- e -t/RC ] V R C

3. How much charge is on the capacitor after 1ms? V = 20V R = 100Ω C= 10μF

4. How long does it take to gain 50% of maximum Charge? V = 20V R = 100Ω C= 10μF

5. How long does it take to gain 100% of maximum Charge? V = 20V R = 100Ω C= 10μF

6. We can use a resistor to slow the discharging of the capacitor. -Current varies with time. -The capacitor is now driving the current -As the capacitor discharges, the voltage drops - V C = V R Charge on capacitor varies with time: q = q o [ e -t/RC ] R C (charged)

7. How much charge is left on the capacitor after 1ms? V = 20V R = 100Ω C= 10μF

8. How long does it take to lose 70% of maximum Charge? V = 20V R = 100Ω C= 10μF

9. What is the current through the battery in very short term? What is the current through the battery in the long term? V =20V R 2 = 10 Ω C = 2μF R 1 = 5 Ω

10. After a long time, what is the voltage drop across the Capacitor? V =20V R 2 = 10 Ω C = 2μF R 1 = 5 Ω