Edwin Hall: Difference between revisions

From Physics Book
Jump to navigation Jump to search
(Created page with "==Thermodynamics== This topics focuses on energy work of a system but it can only deal with a large scale response to heat in a system. '''Thermodynamics''' is the study of...")
 
No edit summary
 
(19 intermediate revisions by the same user not shown)
Line 1: Line 1:
==Thermodynamics==
[[File:Edwin Hall.jpg|200px|thumb|right|Edwin H. Hall]]


This topics focuses on energy work of a system but it can only deal with a large scale response to heat in a system.  '''Thermodynamics''' is the study of the work, heat and energy of a system.  The smaller scale gas interactions can explained using the kinetic theory of gases.  There are three fundamental laws that go along with the topic of thermodynamics.  They are the zeroth law, the first law, and the second law.  These laws help us understand predict the the operation of the physical system.  In order to understand the laws, you must first understand thermal equilibrium.  [[Thermal equilibrium]] is reached when a object that is at a higher temperature is in contact with an object that is at a lower temperature and the first object transfers heat to the latter object until they approach the same temperature and maintain that temperature constantly.  It is also important to note that any thermodynamic system in thermal equilibrium possesses internal energy. 
==Personal Background==


===Zeroth Law===
Edwin Herbert Hall was born in Great Falls, ME on November 7, 1855 to Joshua Emergy Hall and Lucy Ann Hilborn Hall. He got his primary education at the local district school and prepared for college by attending "Gorhma Seminary" for two years. Before Hall was 16, he got into Bowdoin College in Brunswick, Maine and graduated as valedictorian of his class in 1875 with a Bachelor of Arts degree. After graduation, he served as principal of Gould's Academy in Bethel, Maine from 1875-1876,and he served as principal of Brunswick High School in Brunswick, Maine from 1876-1877.


The zeroth law states that if two systems are at thermal equilibrium at the same time as a third system, then all of the systems are at equilibrium with each other.  If systems A and C are in thermal equilibrium with B, then system A and C are also in thermal equilibrium with each other.  There are underlying ideas of heat that are also important. The most prominent one is that all heat is of the same kind. As long as the systems are at thermal equilibrium, every unit of internal energy that passes from one system to the other is balanced by the same amount of energy passing back. This also applies when the two systems or objects have different atomic masses or material.
After two years of teaching, he decided to further study physics, and in the fall of 1877, he entered Johns Hopkins University as a graduate student in physics. He wrote, "I should perhaps have studied law, if I had not felt myself unfitted to advocate a cause in which I did not believe. I turned to science, after two years of school teaching, because it was progressive and satisfied my standards of intellectual and moral integrity, not because I had any passionate love of it or felt myself especially gifted for scientific undertakings." While working under Henry Augustus Rowland, he discovered the Hall Effect in 1879. He was trying to find an answer to the question posed by Maxwell as to whether the resistance of a coil excited by a current was affected by the presence of a magnet. In 1895, he became a physics professor at Harvard and worked until his retirement in 1921.He died on November 20, 1938.


====A Mathematical Model====
==Scientific Contribution==


If A = B and A = C, then B = C
[[File:hall.gif|400px|thumb|right|Hall Effect]]
A = B = C


====A Computational Model====
===Hall Effect===


How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]
When a magnetic field is applied to a conductor or a semiconductor, electromotive force (EMF) is created perpendicular to the direction of the current and the magnetic field. This phenomenon is related to the moving charge in the current. The magnetic field that is perpendicular to the current-carrying wire makes the moving charge go to one side due to the Lorentz Force.


===First Law===
==Industrial Contribution==
[[File:hall sensor.jpg|180px|thumb|right|Hall Sensor]]
[[File:Hall_sensor.gif|180px|thumb|right|A wheel containing two magnets passing by a Hall effect sensor]]


The first law of thermodynamics defines the internal energy (E) as equal to the difference between heat transfer (Q) ''into'' a system and work (W) ''done by'' the system.  Heat removed from a system would be given a negative sign and heat applied to the system would be given a positive sign.  Internal energy can be converted into other types of energy because it acts like potential energy.  Heat and work, however, cannot be stored or conserved independently because they depend on the process.  This allows for many different possible states of a system to exist.  There can be a process known as the adiabatic process in which there is no heat transfer.  This occurs when a system is full insulated from the outside environment.  The implementation of this law also brings about another useful state variable, '''enthalpy'''. 
===Hall Effect Sensor===


====A Mathematical Model====
====What is the Hall Effect Sensor?====


E2 - E1 = Q - W
A device that changes its output voltage depending on the intensity of the magnetic field. It is based on the Hall Effect.


==Examples==
====How does it work?====


Be sure to show all steps in your solution and include diagrams whenever possible
Even if the current runs in the same direction, depending on the sign of the moving charges, the direction of the created electric field can vary. Also, the intensity of the electric field changes in response to the density of the moving charges. Using these phenomena, the intensity of the current-carrying moving charge in a solid can be measured, and in a semiconductor, the free electron can be identified


===Simple===
====The usage of the Hall Sensor====
===Middling===
===Difficult===


==Connectedness==
Sensing the continuous current
#How is this topic connected to something that you are interested in?
Sensing the alternating current
#How is it connected to your major?
Measuring the intensity of the magnetic field
#Is there an interesting industrial application?
Detecting the polarity of the current
 
Sensing temperature by detecting the intensity of the magnetic field in the Ferrite-Magnet
==History==
 
Put this idea in historical context. Give the reader the Who, What, When, Where, and Why.


== See also ==
== See also ==
Line 47: Line 43:
===Further reading===
===Further reading===


Books, Articles or other print media on this topic
Bridgman, P. W. Biographical Memoir of Edwin Herbert Hall, 1855-1938


===External links===
===External links===


Internet resources on this topic
http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/hall-edwin.pdf
 
http://www.electronics-tutorials.ws/electromagnetism/hall-effect.html
 
http://farside.ph.utexas.edu/teaching/302l/lectures/node74.html
 
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/hall.html


==References==
==References==


https://www.grc.nasa.gov/www/k-12/airplane/thermo0.html
http://www.britannica.com/science/Hall-effect#ref273169
http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/thereq.html
 
http://www.nndb.com/people/130/000099830/
 
https://nitum.wordpress.com/2012/09/28/biography-of-edwin-herbert-hall/


[[Category:Which Category did you place this in?]]
[[Category:Notable Scientists]]

Latest revision as of 20:20, 30 November 2015

Edwin H. Hall

Personal Background

Edwin Herbert Hall was born in Great Falls, ME on November 7, 1855 to Joshua Emergy Hall and Lucy Ann Hilborn Hall. He got his primary education at the local district school and prepared for college by attending "Gorhma Seminary" for two years. Before Hall was 16, he got into Bowdoin College in Brunswick, Maine and graduated as valedictorian of his class in 1875 with a Bachelor of Arts degree. After graduation, he served as principal of Gould's Academy in Bethel, Maine from 1875-1876,and he served as principal of Brunswick High School in Brunswick, Maine from 1876-1877.

After two years of teaching, he decided to further study physics, and in the fall of 1877, he entered Johns Hopkins University as a graduate student in physics. He wrote, "I should perhaps have studied law, if I had not felt myself unfitted to advocate a cause in which I did not believe. I turned to science, after two years of school teaching, because it was progressive and satisfied my standards of intellectual and moral integrity, not because I had any passionate love of it or felt myself especially gifted for scientific undertakings." While working under Henry Augustus Rowland, he discovered the Hall Effect in 1879. He was trying to find an answer to the question posed by Maxwell as to whether the resistance of a coil excited by a current was affected by the presence of a magnet. In 1895, he became a physics professor at Harvard and worked until his retirement in 1921.He died on November 20, 1938.

Scientific Contribution

Hall Effect

Hall Effect

When a magnetic field is applied to a conductor or a semiconductor, electromotive force (EMF) is created perpendicular to the direction of the current and the magnetic field. This phenomenon is related to the moving charge in the current. The magnetic field that is perpendicular to the current-carrying wire makes the moving charge go to one side due to the Lorentz Force.

Industrial Contribution

Hall Sensor
A wheel containing two magnets passing by a Hall effect sensor

Hall Effect Sensor

What is the Hall Effect Sensor?

A device that changes its output voltage depending on the intensity of the magnetic field. It is based on the Hall Effect.

How does it work?

Even if the current runs in the same direction, depending on the sign of the moving charges, the direction of the created electric field can vary. Also, the intensity of the electric field changes in response to the density of the moving charges. Using these phenomena, the intensity of the current-carrying moving charge in a solid can be measured, and in a semiconductor, the free electron can be identified

The usage of the Hall Sensor

Sensing the continuous current Sensing the alternating current Measuring the intensity of the magnetic field Detecting the polarity of the current Sensing temperature by detecting the intensity of the magnetic field in the Ferrite-Magnet

See also

Are there related topics or categories in this wiki resource for the curious reader to explore? How does this topic fit into that context?

Further reading

Bridgman, P. W. Biographical Memoir of Edwin Herbert Hall, 1855-1938

External links

http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/hall-edwin.pdf

http://www.electronics-tutorials.ws/electromagnetism/hall-effect.html

http://farside.ph.utexas.edu/teaching/302l/lectures/node74.html

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/hall.html

References

http://www.britannica.com/science/Hall-effect#ref273169

http://www.nndb.com/people/130/000099830/

https://nitum.wordpress.com/2012/09/28/biography-of-edwin-herbert-hall/

Retrieved from "http://www.physicsbook.gatech.edu/index.php?title=Edwin_Hall&oldid=5286"