- #1

Tekneek

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## Homework Statement

The voltage across the capacitor is 10V when t<0

The switch is closed at t=0

I have to find the diff eq. in terms of

**Vs, C, R**by balancing the current at node Vc(t). But i am not sure whether the Vs is 0 or 10V at t<0

## The Attempt at a Solution

I am assuming Vs = 0 at t<0 since the voltage across capacitor is 10V. Also, I am not sure what current balance at the node means...I mean when the switch is closed the current through the capacitor is the same as current through the resistor. So,

iR = iC

(Vc/R) = C (dVc/dt)

How do i write this in term of Vs? Isn't the current through the resistor Vc/R since Vs is 0 at the beginning?