- #1

likephysics

- 636

- 2

## Homework Statement

You have one capacitor C1 (1uF) charged to 10V.

Now the capacitor is switched to charge another capacitor C2 (0.25uF),

Whats the voltage on C2?

Everything's ideal. No loss caps, no wire resistance.

## Homework Equations

## The Attempt at a Solution

I tried,

Q1=C1V1

Q2=C2V2

total charge will be constant, so Qtotal, Qt=CtV

Both caps are in series, so Qt= (C1+C2)V

(C1+C2)V = C1V1+C2V2

V2 is 0v

V = C1V1/(C1+C2)

So, V=8V.

But when I do E = 0.5*C*V^2 for C1. (80uJ)

and then for both the caps(32uJ and 8uJ), the numbers don't add up.