- #1
darkar
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I am curious about is there any energy can be found / get in the magnetic field?
Is There Energy in Magnetic Fields?
- Thread starter darkar
- Start date
In summary, in classical electrodynamics, a magnetic field in vacuum has an energy density of u0B2. This energy can be extracted by using a conductor moving at an angle through the field to produce a potential difference and run a current. The energy for this comes from the original magnetic field, which was set up by an external source.
- #2
zefram_c
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Yes: in classical electrodynamics, a magnetic field in vacuum has an energy density of u0B2. This energy can be extracted. For example, a conductor moving at an angle through a magnetic field develops a potential difference between its endpoints. This can be used to run a current, thus performing work. The energy for that could only have come from the field, and indeed the resulting assembly produces a magnetic field that partially cancels the original field, maintaining energy conservation.
- #3
darkar
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Then where is the energy come from?
- #4
zefram_c
- 259
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Which energy are you asking about exactly? The original energy of the magnetic field? If so, that energy came from the act of setting up the magnetic field in the first place. See this for a simple example:
http://farside.ph.utexas.edu/teaching/302l/lectures/node86.html
http://farside.ph.utexas.edu/teaching/302l/lectures/node86.html
- #5
Creator
- 566
- 6
zefram_c said:
Uh...you of course meant to say energy density is B2/2u0, right zefram?
Creator
- #6
zefram_c
- 259
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Indeed that's what I meant. Can't everyone take a nap in class every now and then?
FAQ: Is There Energy in Magnetic Fields?
What is the definition of energy in a magnetic field?
Energy in a magnetic field refers to the potential energy that is stored in a system due to the presence of magnetic fields and the interactions between magnetic objects.
What are the different types of energy associated with magnetic fields?
There are two main types of energy associated with magnetic fields: magnetic potential energy, which is the energy stored in a magnetic field, and kinetic energy, which is the energy of motion of charged particles moving through a magnetic field.
How is energy transferred in a magnetic field?
Energy can be transferred in a magnetic field through the movement of charged particles, such as electrons, which can generate an electric current. This current can then be used to power electronic devices or perform work.
What factors affect the amount of energy in a magnetic field?
The amount of energy in a magnetic field is affected by the strength of the magnetic field, the distance between magnetic objects, and the orientation of the magnetic field in relation to the objects.
How is energy in a magnetic field used in everyday life?
Energy in a magnetic field is used in a variety of everyday applications, such as generators, motors, and transformers. It is also used in medical imaging technologies like MRI machines and in powering electronics such as speakers and hard drives.