Minimum Current for Magnetic Levitation: Is It Safe for a Magician's Act?

In summary: I cannot thank you enough.In summary, the magician needs to use a current carrying wire to suspend it just above Earth's surface. He needs to find the magnetic field at the equator and use that to calculate the current needed.
  • #1
w3390
346
0

Homework Statement


Your friend wants to be a magician and intends to use Earth's magnetic field to suspend a current-carrying wire above the stage. He asks you to estimate the minimum current needed to suspend the wore just above Earth's surface at the equator (where the Earth's magnetic field is horizontal). Assume the wire has a linear mass density of 10g/m. Would you advise him to proceed with his plans for this act?


Homework Equations


dF=IdlxB, where dlxB is a cross product

The Attempt at a Solution


I am having trouble understanding where to start. I am having trouble visualizing the problem and I don't know how to incorporate the linear mass density into anything. My book does not go over anything like this. Help on how to start would be much appreciated.
 
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  • #3
I do not understand how to get I from the equations in your second link. I understand what they mean and I have used them a lot, but I am not sure how the force is going to come into play.
 
  • #4
w3390 said:
I do not understand how to get I from the equations in your second link. I understand what they mean and I have used them a lot, but I am not sure how the force is going to come into play.

Well it will take real magic then to suspend a wire.

If the qV got you then try

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/forwir.html#c1
 
  • #5
Thank you so much. That last link does an amazing job at helping the visualization process. Once I could see what was happening, it made complete sense.
 

1. What is the difference between electric current and magnetic field?

Electric current refers to the flow of electric charge, while magnetic field refers to the region around a magnet or a current-carrying wire where magnetic forces can be detected.

2. How are currents and magnetic fields related?

Currents and magnetic fields are related through electromagnetism. A current flowing through a wire creates a magnetic field around the wire, and a changing magnetic field can induce a current in a nearby wire.

3. What is the role of currents and magnetic fields in everyday life?

Currents and magnetic fields play a crucial role in many modern technologies, such as electric motors, generators, and transformers. They also have applications in medical imaging, particle accelerators, and magnetic levitation trains.

4. Can currents and magnetic fields be harmful to humans?

In large amounts, currents and magnetic fields can be harmful to humans. For example, exposure to high levels of magnetic fields has been linked to an increased risk of cancer. However, the levels of exposure from everyday devices are typically too low to cause harm.

5. How can we measure currents and magnetic fields?

Currents can be measured using instruments such as ammeters, while magnetic fields can be measured using devices called magnetometers. These instruments can detect the strength and direction of magnetic fields and the amount of current flowing through a circuit.

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