- #1
qh4305
- 4
- 1
Why is the energy of a circuit placed in a magnetic field at infinity zero?
Exploring the Zero Energy of a Circuit in a Magnetic Field
In summary, the conversation discusses the concept of energy in a circuit placed in a magnetic field at infinity and the confusion surrounding it. The formula for calculating the magnetic energy of a closed circuit in a magnetic field is mentioned, but the context and scenario are not clear. Some general comments are provided about energy created in a loop of wire from magnetic fields, including the fact that DC magnetic fields do not induce energy and the energy from time varying fields is proportional to their intensity.
- #2
berkeman
Mentor
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Because the batteries get drained on the way there? It's a long trip, after all. 
But seriously, what are you talking about? Are you confusing gravitational potential energy (GPE) with electrical energy?
But seriously, what are you talking about? Are you confusing gravitational potential energy (GPE) with electrical energy?
- #3
qh4305
- 4
- 1
I had a bit of a problem with proving a formula, and I made myself an assumption that the energy of the circuit placed in a magnetic field at infinity would be zero, but maybe that doesn't hold true for science, engineering, and so on. The formula that I am proving is the formula for calculating the magnetic energy of a closed circuit in a magnetic field, I used the convention that the work of the magnetic force is equal to the decrease in potential energy, but now I think it is not quite right. Can you help me prove this energy formula?berkeman said:Because the batteries get drained on the way there? It's a long trip, after all.
But seriously, what are you talking about? Are you confusing gravitational potential energy (GPE) with electrical energy?
p/s:
sorry for my english
- #4
sophiecentaur
Science Advisor
Gold Member
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Show us the formula and the context of your question. That may help you to get an answer.qh4305 said:
- #5
DaveE
Science Advisor
Gold Member
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I think we are all confused about the scenario you are asking about. What's at infinity, compared to what? What sort of magnetic field? What made it? What do you mean by a circuit? Is it just a loop of wire?
Maybe a simple sketch would help.
Maybe a simple sketch would help.
- #6
qh4305
- 4
- 1
sophiecentaur said:
- #7
qh4305
- 4
- 1
sophiecentaur said:
Is this a correct proof?
- #8
DaveE
Science Advisor
Gold Member
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Sorry, I still don't know what you're asking about. Maybe someone else will figure something out.
Here are a couple of general comments about energy created in a loop of wire from magnetic fields:
- DC (static) magnetic fields don't induce any voltage and thus no energy in a "circuit".
- The energy from a time varying magnetic field will be proportional to it's intensity.
- Time varying fields propagate to fill more space and as a result their amplitude decreases. As the distance from the source goes to infinity, the amplitude approaches zero.
- The only thing that matters to the circuit in question is the magnetic field values at the circuit. The only value in examining the field at distant points is if that helps characterize it at the circuit.
- This is classical physics. Most of this doesn't make sense if you consider that a photon could travel the length of the universe, or a short distance, and carry with it the same energy in either case.
Here are a couple of general comments about energy created in a loop of wire from magnetic fields:
- DC (static) magnetic fields don't induce any voltage and thus no energy in a "circuit".
- The energy from a time varying magnetic field will be proportional to it's intensity.
- Time varying fields propagate to fill more space and as a result their amplitude decreases. As the distance from the source goes to infinity, the amplitude approaches zero.
- The only thing that matters to the circuit in question is the magnetic field values at the circuit. The only value in examining the field at distant points is if that helps characterize it at the circuit.
- This is classical physics. Most of this doesn't make sense if you consider that a photon could travel the length of the universe, or a short distance, and carry with it the same energy in either case.
FAQ: Exploring the Zero Energy of a Circuit in a Magnetic Field
What is the concept of zero energy in a circuit?
The concept of zero energy in a circuit refers to the state where there is no net flow of electrical energy in the circuit. This means that the energy input into the circuit is equal to the energy output, resulting in a balanced system.
How does a magnetic field affect the energy of a circuit?
A magnetic field can induce a current in a circuit, which can then lead to a change in the energy of the circuit. This change in energy is due to the interaction between the magnetic field and the electric charges in the circuit.
What is the significance of exploring the zero energy of a circuit in a magnetic field?
Exploring the zero energy of a circuit in a magnetic field can help us understand the behavior and properties of circuits in different conditions. It also allows us to optimize the design and efficiency of circuits by minimizing energy losses.
How can we measure the zero energy of a circuit in a magnetic field?
The zero energy of a circuit in a magnetic field can be measured by using various instruments such as an ammeter, voltmeter, and oscilloscope. These instruments can measure the current, voltage, and waveform of the circuit to determine its energy state.
What are some practical applications of exploring the zero energy of a circuit in a magnetic field?
Some practical applications of exploring the zero energy of a circuit in a magnetic field include the development of more efficient electrical devices, such as motors and generators. It can also be used in renewable energy systems, such as wind turbines, to optimize energy production and reduce energy losses.