Nikola Tesla

Nikola Tesla was the physicist who "Lit the World." He is most famous for his work in alternating current power production, although in PHYS 2112, he will be known for his solution to the rotational magnetic field. His last name was dedicated to the SI unit for Magnetic Field Strength, or Magnetic Flux Density. He is patented for his alternating electric current generator, which utilizes coils of current to magnetically induce an alternating current.

The Main Idea

Tesla's AC generator is a successful application of his rotational magnetic field discovery. His invention can be seen in the picture to the right; the coils of current act out of phase from each other to create an alternation in current that can be repeated many thousands of times per second. Furthermore, AC current could travel long distances with high amounts of voltage, unlike Thomas Edison's Direct Current solution. He recognized that these benefits of alternating current would be more effective for power production than Edison's direct current system. The two men were in competition with each other until he demonstrated the abilities of alternating current at the 1893 Chicago World Columbian Exposition. The culminating achievement of Tesla's AC power generation was a hydroelectric power plant installed at Niagara Falls in 1895.

Important Equations

The following equation for the magnitude of a rotational magnetic field produced by a wire is as follows:

[math]\displaystyle{ B_{wire}=\frac{\mu _{0}{I}}{2\pi R} }[/math]

This is the general equation for the magnetic field around an infinitely long wire, or more simply, where [math]\displaystyle{ R \lt \lt \lt L }[/math]. It is the sum of the magnetic fields caused by the tiny segments of current if you were to chop up the wire into little pieces, integrated down the entire length of the wire.

This is a very important concept in this course. It follows the right hand rule, just like many other concepts do. If you point the thumb of your right hand in the direction of current flowing through the wire, your fingers will curl in the direction of magnetic field. The field strength is given by the above equation, dependent on distance from the wire and amount of current running through the wire. For more information about the Magnetic Field equation, see the page Magnetic Field and its special case subcategories.

We can see from this equation that the units simplify to: [math]\displaystyle{ kg*s^{-2}*A^{-1} }[/math]. This is equivalent to the unit Tesla, given by [math]\displaystyle{ T }[/math].

Visualization

While it is not necessary to know how Tesla's AC generator works, it is a really neat application of rotational magnetic fields.

We know that coils of current produce a magnetic field that is uniform and perpendicular to the face of the coil (see Magnetic Field of a Loop), so the above image's arrows show the net magnetic field as the inner coils come in phase and out of phase with the outer coils.

Connectedness

Nikola Tesla is relevant because his invention for AC power generation. Thanks to Tesla, homes can have electricity wired to them! The lights in your room, the charging cable to your laptop, and everything else that plugs into an outlet can be traced back to an AC generator. With DC current generation, this couldn't be the case unless you lived right down the block from a power plant.

Nikola Tesla also was very curious about wireless communication and transmission, and his invention of the Tesla Coil helped father radio and television technology. He is credited with working on fluorescent lights, laser beams, turbines, and vertical take-off aircraft (shout out to all the Electrical and Aerospace Engineers).

Biography

Nikola Tesla was born to Milutin Tesla and Djuka Mandic on July 10th, 1856. He is a native Croatian, and he studied at Realschule, Karlstadt, the Polytechnic Institute of Graz, Austria and the University of Prague. He worked as an electrical engineer in Budapest after studying physics and mathematics, although he later moved to America to work for Thomas Edison. It was his childhood dream "to harness the power of Niagara Falls," which he achieved by the end of his career (www.TeslaSociety.com).

See also

Visit Magnetic Field and all of its subcategories for a more in-depth look into the equations debriefed above. Also, see Magnetic Fields (under the category Maxwell's Equations) to see how Magnetic Field strength is conceptually related to Magnetic Flux Density, since they share the units Tesla.

External links

See The Tesla Memorial Society of New York for more information about Nikola Tesla. Also, see The Tesla Collection for a compilation of papers and studies on Tesla's work and relevant topics.

References

This section contains the the references you used while writing this page