1. The problem statement(adsbygoogle = window.adsbygoogle || []).push({});

http://s685.photobucket.com/albums/vv212/dewdr0p714/?action=view¤t=5circuittakehometest1.jpg

1) Determine the equivalent capacitance of the circuit

2) How many RC time constants are needed for the charge on the capacitors to reach 75% of their final charge?

2. Relevant equations

q= q0 (1 - e^-t/RC)

q=CV

3. The attempt at a solution

I tried to find the equivalent capacitance....this was my method but I am not sure if it is correct.

Equiv Capac = (15*10^-6)(10*10^-6) + (10*10^-6)(10*10^-6) + (15*10^-6)(10*10^-6) / (10*10^-6) + (10*10^-6)

Equiv Capac = 20*10^-6 Farads

For the RC time constants question, I think I need the capacitance to be able to solve it and with the capacitance that I got, I could find q thru the equation q=CV....after that I am unsure about how to proceed with question #2. Does the q get inputted for q or q0?

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# Capacitance of circuit & RC time constant

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