Electrons enter charged capacitor

Thread starter Xuran Wu
Start date Nov 6, 2023
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Capaci tors Electromagentic

In summary, when electrons enter a charged capacitor, they accumulate on one plate, increasing its negative charge, while the opposing plate becomes positively charged due to the loss of electrons. This movement of electrons creates an electric field between the plates, allowing the capacitor to store energy. The amount of charge stored is proportional to the voltage across the capacitor and its capacitance.

Nov 6, 2023

Xuran Wu

Homework Statement: Two electrons enter a region between charged capacitor plates with equal speed v Electron A is directed horizontally to the left while electron B is directed at 30 degrees below the horizontal. Each electron makes it to the left-hand plate. Which one of the following choices best compares the speeds of the charges(vA, vB)upon arrival at the left plate? Consider only the electrons A and B’s interactions with the constant field between the plates, ignoring any relativistic effects.
A. vA>vB
B. vA=vB
C.vA<vB
D. The answer depends on the size of the plate separation,d.
E. The answer depends on the magnitude of the charge, Q, on each plate

Relevant Equations: C=QV

I cannot understand. I think that the constant electric fields and the direction the electrons ahead of cannot change the speed, but I can’t be sure about that. I really hope that someone can help me on that, thank you very mouch.

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Nov 6, 2023

kuruman

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Is there a force acting on each charge? If so, what is it and in what direction? Note that the Earth's gravitational field near the Earth's surface is also constant. Can you draw a parallel between the two situations?

FAQ: Electrons enter charged capacitor

What happens to electrons when they enter a charged capacitor?

When electrons enter a charged capacitor, they accumulate on the plate that is connected to the negative terminal of the power supply. This causes a build-up of negative charge on that plate, while the opposite plate becomes positively charged due to the displacement of electrons.

How does the presence of electrons affect the electric field within a charged capacitor?

The presence of electrons on the negative plate of the capacitor creates an electric field that points from the positive plate to the negative plate. The strength of this electric field is directly proportional to the amount of charge on the plates and inversely proportional to the distance between them.

Can a charged capacitor continue to accept electrons indefinitely?

No, a charged capacitor cannot continue to accept electrons indefinitely. As more electrons accumulate on the negative plate, the potential difference between the plates increases until it matches the voltage of the power supply. At this point, the capacitor is fully charged and no more electrons can flow onto the plates.

What is the role of dielectric material in a charged capacitor with respect to electrons?

The dielectric material in a charged capacitor increases its capacitance by reducing the electric field within the capacitor for a given charge on the plates. This allows the capacitor to store more electrons (and thus more charge) for the same applied voltage. The dielectric material achieves this by polarizing in response to the electric field, which reduces the effective field between the plates.

How do electrons move in a circuit containing a charged capacitor?

In a circuit containing a charged capacitor, electrons move from the negative terminal of the power supply to the negative plate of the capacitor, while electrons are simultaneously removed from the positive plate of the capacitor to the positive terminal of the power supply. This movement continues until the capacitor is fully charged and the voltage across it equals the supply voltage, at which point the current stops flowing.