I have to solve this problem for a circuit. Its a capacitor, a resistor and another capacitor all in series.(adsbygoogle = window.adsbygoogle || []).push({});

Both capacitances are the same, 1uF, and the resistor is 100k-Ohm.

I have to find the current function of time.

What I did was use KVL to get:

[tex] - \frac{1}{c_1} \int i(t)dt + v_1 (t_0) + \frac{1}{c_2} \int i(t)dt + v_2 (t_0) + R i(t) = 0 [/tex]

Then I took the derivative to get:

[tex] - \frac{1}{c_1} i(t) + R \frac {di}{dt} + \frac{1}{c_2}i(t) =0[/tex]

Which simplifies to:

[tex] R( \frac{1}{c_2} - \frac {1}{c_1} )^{-1} \frac {di}{dt} +i(t) = 0 [/tex]

But the two capacitances have the same value, which means that RC-eq is zero. That's wrong....hmmmmmmmmm

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Find current for circuit with capacitor, resistor, capacitor in series

**Physics Forums | Science Articles, Homework Help, Discussion**