1. Monday February 23 Lecture 15 RC Circuits Electricity in the Nervous System

2. Capacitor Combinations Slide 23-24

3. Which of the following combinations of capacitors has the highest capacitance? 1.A 2.B 3.C 4.D

4. Which of the following combinations of capacitors has the lowest capacitance? 1.A 2.B 3.C 4.D

5. Which of the following combinations of capacitors has the lowest capacitance? 1.A 2.B 3.C 4.D

6. RC Circuit Charge or discharge a capacitor, C, through a resistor, R. Start with discharge: See diagram R=40,000Ω C= 3000 μF E = 3.0 V

7. What current flows just after switch is closed (t=0)? E = 3 V and Vc = 0, so I = E /R = 3.0/300=.01 A What is charge on C at t=0.01 s? (approx)

8. At t = 0.01 s Q(.01) = Q(0)-I(0)*.01 = ? – What is Vc(0.01) ? Q(.02) = ? – Vc(0.02) ?

9. All capacitors have V 0 = 5.0v at t=0 when switches are closed. Which has the lowest voltage at t = 1s? 1.A 2.B 3.C 4.D