Capacitors and Electric Fields

• unseensoul

unseensoul

There are no electric fields outside of a charged capacitor as they are canceled out due to superposition, right?! So why is there a flow of current when a cable is connected to both ends of the capacitor?

I was told that there might be an E field in the wires. How come? Where does it come from?

A charged capacitor can be discharged by connecting the plates together.
That is what you do when you connect the two ends of a charged capacitor by a piece of wire.

A capacitor is made by making layers of metal and dielectric in a spiral on a central rod.
This means that one of the layers of metal must be on the outside of the capacitor. ie they can't both be on top.
So, this plate of the capacitor would certainly have a field around it if the capacitor was charged.
Maybe your first assertion isn't correct for normal capacitors?

Not sure what you mean by an "E" field. The leads of a capacitor can certainly have a voltage between them. There is a capacitor in all microwave ovens that is very capable of killing you.

1. What is a capacitor and how does it work?

A capacitor is an electrical component that stores energy in the form of an electric field. It consists of two conductive plates separated by an insulating material, known as a dielectric. When a voltage is applied to the capacitor, it charges by storing positive and negative charges on the plates. The capacitor can then release this stored energy when needed.

2. What is the role of an electric field in a capacitor?

The electric field is the driving force behind the functioning of a capacitor. When a voltage is applied, the electric field between the two plates of the capacitor causes the electrons to accumulate on one plate and the positive charges on the other plate. This creates a potential difference between the plates, allowing the capacitor to store energy.

3. How are capacitors used in electronic circuits?

Capacitors have a wide range of applications in electronic circuits. They can be used for filtering, smoothing, and regulating voltage signals. They are also commonly used in timing circuits, signal coupling, and energy storage in power supplies.

4. What factors affect the capacitance of a capacitor?

The capacitance of a capacitor is affected by the surface area of the plates, the distance between the plates, and the type of dielectric material used. A larger surface area and a smaller distance between the plates result in a higher capacitance. Different types of dielectric materials have different permittivity values, which also affect the capacitance.

5. How do capacitors store and release energy?

Capacitors store energy in the form of an electric field between their plates. When a voltage is applied, the capacitor charges by storing positive and negative charges on the plates. When the capacitor is connected to a circuit, it can release this stored energy in the form of an electric current. The amount of energy stored in a capacitor is directly proportional to its capacitance and the square of the voltage applied.