Connecting two charged capacitors

In summary, the conversation discusses the setup of two capacitors with different capacities being charged in series by a voltage source and then being connected to each other. The equations Q=CV and 1/Ctot= (1/C1 + 1/C2) are mentioned for calculating total capacity and charge. The experts suggest drawing a picture to understand the charge and voltage when the capacitors are connected to each other.
  • #1
Eitan Levy
259
11

Homework Statement


One capacitor with a capacity of 6μF and another with a capacity of 12μF are charged by being connected in a series to a voltage source with an electrive force of 660V. After that, we disconnect the capacitors from the source and connect them to each other.
What is the charge and the voltage of each capacitor if we connect each positive plate to the other's positive plate?
What is the charge and the voltage of each capacitor if we connect each positive plate to the other's negative plate?

Homework Equations


Q=CV

The Attempt at a Solution


In the first case I think that the potentials will be equal, but I am still not sure how to calculate this. In the second case the charges will be equal, but again, I can't figure how to calculate it.
 
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  • #2
You wrote that the capacitor are connected in series, so to calculate the total capacity you can use the formula: 1/Ctot= (1/C1 + 1/C2)
Once you find Ctot you can use it in the Q=CV formula and calculate the charge, because you have to total voltage that is 660V.
 
  • #3
Grands said:
You wrote that the capacitor are connected in series, so to calculate the total capacity you can use the formula: 1/Ctot= (1/C1 + 1/C2)
Once you find Ctot you can use it in the Q=CV formula and calculate the charge, because you have to total voltage that is 660V.
This is the part that I knew what to do in, I don't what to do after the capacitors are connected to each other in each case.
 
  • #4
Eitan Levy said:
What is the charge and the voltage of each capacitor if we connect each positive plate to the other's positive plate?
What is the charge and the voltage of each capacitor if we connect each positive plate to the other's negative plate?

. The attempt at a solution
In the first case I think that the potentials will be equal, but I am still not sure how to calculate this. In the second case the charges will be equal, but again, I can't figure how to calculate it.

I think I would not calculate anything, I would just draw a picture. What are you putting in contact with what, and what are the charges going to do?
 

What is a charged capacitor?

A capacitor is a device that stores electrical energy in the form of an electric charge. It consists of two conductive plates separated by an insulating material, known as a dielectric. When a voltage is applied to the capacitor, one plate becomes positively charged and the other becomes negatively charged, creating an electric field between them.

How do you connect two charged capacitors?

To connect two charged capacitors, you need to connect the positive plate of one capacitor to the negative plate of the other capacitor. This can be done by using a wire or any other conductive material. The two capacitors will then share their charges and the total capacitance will increase.

What is the total capacitance when two charged capacitors are connected?

The total capacitance when two charged capacitors are connected depends on the individual capacitances of the two capacitors. If the two capacitors have the same capacitance, the total capacitance will be twice the individual capacitance. If the two capacitors have different capacitances, the total capacitance can be calculated using the formula 1/Ctotal = 1/C1 + 1/C2, where C1 and C2 are the individual capacitances.

What are the effects of connecting two charged capacitors?

Connecting two charged capacitors has several effects. Firstly, the total capacitance increases, which means that the capacitors can store more charge. Secondly, the voltage across each capacitor decreases because the charges are shared between them. Lastly, the energy stored in the system increases due to the increase in capacitance.

Can two charged capacitors with different voltages be connected?

Yes, two charged capacitors with different voltages can be connected. However, it is important to note that the final voltage across each capacitor will be different than their initial voltages. The final voltage can be calculated using the formula Vfinal = (C1*V1 + C2*V2)/(C1 + C2), where V1 and V2 are the initial voltages and C1 and C2 are the individual capacitances.

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