# AC Theory question with capacitors

• jami8337
In summary, three uncharged 1uF capacitors were connected in parallel and then connected to a 100V power supply via a 1MΩ resistor. After 2 seconds, the capacitors were removed and connected in series, allowing for discharge through a 10kΩ resistor. To find the discharge current, the general discharge equation q=q e^(-t/RC) was used, taking into account the addition of voltages and capacitances in series. The values for R and C will differ for charging and discharging. The discharge current can be calculated at the start of discharge and 3ms later using this equation.
jami8337
Three uncharged capacitors each of 1uF are connected in parallel and the combination connected to a 100V power supply via a 1MΩ resistor. After 2s the capacitors are removed, connected in series and the new combination allowed to discharge through a 10kΩ resistor.

Find the discharge current at the start of discharge and 3ms late

I was just thinking the general discharge equation:
q=q e^(-t/RC)

I have no idea where to go with it though so if anyone can point me in the right direction id be very grateful

• Voltages in series add together.

• Capacitances in series add according to: 1/C = 1/C1 + 1/C2 + ...

I was just thinking the general discharge equation:
q=q e^(-t/RC)
Yes, that's what you use. First for the capacitors charging, then for them discharging. R and C will differ for the charging and discharging situations.

Last edited:

## 1. What is a capacitor?

A capacitor is an electronic component that stores and releases electrical energy in the form of an electric charge. It consists of two conductive plates separated by an insulating material, known as a dielectric.

## 2. How does a capacitor work?

A capacitor works by storing electrical energy in an electric field between its two plates. When a voltage is applied, one plate accumulates a positive charge while the other accumulates a negative charge. The dielectric material between the plates prevents the charges from coming into contact, thus storing the energy.

## 3. What is the unit of measurement for a capacitor?

The unit of measurement for a capacitor is farad (F). However, capacitors are often measured in microfarads (µF) or picofarads (pF) due to their small sizes.

## 4. What is the difference between a polarized and a non-polarized capacitor?

A polarized capacitor has a positive and a negative terminal, and it must be connected in the correct orientation in a circuit. Non-polarized capacitors do not have a specific positive or negative terminal and can be connected in either direction.

## 5. How does a capacitor affect an AC circuit?

In an AC circuit, a capacitor can store and release energy, which can affect the voltage and current in the circuit. It can also act as a filter, blocking certain frequencies of alternating current and allowing others to pass through.

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