# Capacitors inserted into a circuit with opposite polarities

• Alfaraj
The initial potential difference of 100 V between the two charged capacitors is maintained when they are connected in parallel. However, when the switches are closed, the charges on the plates of the two capacitors redistribute, resulting in a non-zero potential difference between points A and B. The magnitude of this potential difference can be calculated using the equation C = Q / deltaV, where C is the capacitance and Q is the charge. In summary, when switches S1 and S2 are closed, the potential difference between points A and B will not be zero and can be calculated using the capacitance and charge of the capacitors.
Alfaraj

## Homework Statement

Two capacitors C1 = 5 μF and C2 = 2 μF are initially charged to a potential difference of V = 100 V. They are inserted into the circuit with opposite polarities as shown. Switches S1 and S2 are now closed. What is the magnitude of the potential difference between points A and B? (Answer in Volts.)

[PLAIN]http://img833.imageshack.us/img833/557/phyr.jpg

C = Q / deltaV

## The Attempt at a Solution

Since both capacitors have same potential difference since they are connected in parallel. I think the answer should be zero since we would have two opposite-sign voltages.

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No. The voltage will not be zero as the charges are not equal and opposite on the connected plates.

ehild

No. The voltage will not be zero as the charges are not equal and opposite on the connected plates.

ehild

## 1. What happens if capacitors are inserted into a circuit with opposite polarities?

When capacitors are inserted into a circuit with opposite polarities, they will act as a short circuit and discharge quickly. This can cause damage to the capacitors and other components in the circuit.

## 2. Can I reverse the polarity of a capacitor in a circuit?

It is not recommended to reverse the polarity of a capacitor in a circuit. Doing so can damage the capacitor and other components in the circuit. It is best to use a capacitor with the correct polarity for the specific circuit.

## 3. How can I tell the polarity of a capacitor?

The polarity of a capacitor is usually indicated by markings on the capacitor itself. The positive terminal is typically marked with a plus sign (+) while the negative terminal is marked with a minus sign (-). If there are no markings, the longer leg of the capacitor is usually the positive terminal.

## 4. What is the purpose of inserting capacitors with opposite polarities in a circuit?

Inserting capacitors with opposite polarities in a circuit is not recommended and should be avoided. However, in some cases, it can be used as a temporary measure to discharge a capacitor quickly. This should only be done by trained professionals and with caution.

## 5. Can I use capacitors with opposite polarities in series or parallel?

No, it is not recommended to use capacitors with opposite polarities in series or parallel. This can cause imbalances in the circuit and lead to damage or malfunction. It is best to use capacitors with the same polarity in series or parallel.

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