Charge in a Circuit - Potential Energy Explained

• Mar 9, 2004

• #1

speeding electron

65

0

When we connect two points at different potentials in a cell with a conductor, we will have a circuit and charge will flow between the two points. Will each unit charge, just as if it were experiencing an electromagnetic force in free space, have a potential energy by virtue of its position from the point at lower potential it is attracted towards?

Each unit of charge will lose more of its potential energy (all of which it inevitably must lose if it is to reach the end of the circuit) in the loads with higher resistances. But this means that the charge can have different potentials at the same distance from the point at lower energy, depending on how much of the total resistance of the circuit it has gone through. Is there something I'm missing here? Does the force act somehow 'around the circuit', rather than straight?

Help is appreciated.

 

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• Mar 10, 2004

• #2

turin

Homework Helper

2,323

3

Originally posted by speeding electron
Will each unit charge, just as if it were experiencing an electromagnetic force in free space, have a potential energy by virtue of its position from the point at lower potential it is attracted towards?

No, not just like in free space. It will not be in free space, but in a material that conducts, which is a very different situation. The cell has two poles. Why are you disregarding the other one?

Originally posted by speeding electron
Each unit of charge will lose more of its potential energy ... in the loads with higher resistances. But this means that the charge can have different potentials at the same distance from the point at lower energy, ...

That is because the potential field does not necessarily have the same symmetries in this case, as it would in free space. The presense of media (i.e. conductors) distorts the potential field.

 

• Mar 12, 2004

• #3

speeding electron

65

0

OK, thanks for clearing that up.

 

1. What is charge in a circuit?

Charge in a circuit refers to the movement of electric charges, such as electrons, through a closed path or circuit. This movement of charge is what creates an electric current, which is essential for the functioning of electronic devices.

2. How is charge related to potential energy in a circuit?

In a circuit, potential energy refers to the energy stored in the electric field between two points. This energy is directly related to the amount of charge present in the circuit. As the charge moves through the circuit, it gains or loses potential energy depending on the direction of its movement.

3. What factors affect the amount of charge in a circuit?

The amount of charge in a circuit is affected by various factors, including the voltage or potential difference, the resistance of the circuit, and the capacitance. These factors determine how fast the charge flows and how much charge can be stored in a specific circuit.

4. How does the flow of charge affect the behavior of a circuit?

The flow of charge is what drives the functioning of a circuit. As the charge moves through the circuit, it encounters different components, such as resistors and capacitors, which affect its behavior. The flow of charge also determines the amount of current and power in the circuit.

5. How is charge conserved in a circuit?

According to the law of conservation of charge, the total amount of charge in a closed system remains constant. In a circuit, this means that the amount of charge entering a point must be equal to the amount of charge leaving that point. This principle ensures that the circuit remains balanced and functional.