# Homework Help: If we connected the the positive plate of c1 to the negative plate of c2 and vice versa ?

1. Sep 21, 2014

### ABC2233

1. The problem statement, all variables and given/known data
Q1= 200 C
Q2=400 C

2. Relevant equations

Qtotal= Q1+Q2 ?

3. The attempt at a solution

Qtotal=Q1+Q2=400-200=200 C
Is it possible to connect the positive plate of C1 to the negative plate of C2 and vice versa without the capacitor getting explode ?

2. Sep 21, 2014

### Simon Bridge

Yes.

3. Sep 21, 2014

### ABC2233

Thanks.
One other question if I may ask, is those capacitors connected in parallel ?
Can we say that V1=V2 ?

4. Sep 22, 2014

### Simon Bridge

If capacitors are in parallel with each other, then the voltage across one capacitor is also across the other one.

5. Sep 22, 2014

### ABC2233

so as in this picture, it's possible and it's considered parallel, right?

6. Sep 22, 2014

### Simon Bridge

I'd say they were in series because a current will flow around the loop - forming a circuit.
But you wouldn't normally be trying to find equivalent capacitances in that situation.

In a steady-state those capacitors would be considered to be in parallel with each other.
But that would be after the charges have rearranged. Before that, the distinction does not mean much.

7. Sep 23, 2014

### ABC2233

Right.
We had a homework before, we had to calculate the final charge after the rearrangement.

As I have been told, we calculate the final charge after the rearrangement then consider it to be parallel, Right ?

8. Sep 23, 2014

### ehild

It is right.

ehild

9. Sep 23, 2014

### ABC2233

Thanks a lot Simon Bridge & ehild.

10. Sep 23, 2014

### Simon Bridge

That's right.
In the configuration shown in the diagram, the voltages across the capacitors are not the same, because of the way the charges are arranged. After the charges have rearranged, the voltages will be the same.

11. Sep 23, 2014

Thanks.