Inductance
Made by Mackenzie Rideout
Short Description of Topic
The Main Idea
Inductance is intimately connected with Faraday’s law of electromagnetic induction. According to this law there is an induced electromotive force in any circuit whenever the magnetic flux linked with that circuit changes. A circuit carrying a current always has some linked magnetic flux due to that current. A change in the current leads to a change in the flux, and the change in flux in turn gives rise to an induced e.m.f. Furthermore, the induced e.m.f. is always in such a direction that it tends to oppose the change in current: there is a forward e.m.f. if the current is being reduced and a backward e.m.f. if it is being increased.
As seen in figure (A) the induced emf, due to a solenoid, in this case is in such a direction that opposes the change in current. In this case the induced emf acts like a battery placed backwards in comparison of the original one. This, reduces the rate at which the current is increasing.
The opposite happens in figure (B) the induced emf, due to a solenoid in this case, is in such direction that opposes the change in current. In this case the emf acts like a battery placed in the same direction as the original one. This, reduces the rate at which the current decreases.
A Mathematical Model
To be able to successfully compute the inductance of a coil you will have to analyze the magnetic field that surrounds it.
In the case of a solenoid, the magnetic field is 
. For a solenoid this can give you information about the current running through one loop on the solenoid which you can then use to find the current that is running through the entire solenoid from beginning to end. You do this by taking the derivative of the magnetic field with respect to time and then multiplying this result by the number of loops in the solenoid.
A Computational Model
Here is a visual display of the magnetic field in a solenoid 
To understand the inductance lets go step by step through the examples and get the main formula for Inductance.
Examples
Be sure to show all steps in your solution and include diagrams whenever possible
Simple
Emf of an entire solenoid:
Middling
What is the self inductance of a common solenoid?
-The self inductance is the constant in the inductance formula solved above. This means that the self inductance constant for a solenoid is (μ0N/d(piR^2)
Difficult
What is the self-inductance of a solenoid that has 100 loops, a radius of 5 cm, and is 1 meter long.
Connectedness
- This topic is interesting because solenoids are a very common placed tool. It is important to know how they operate in order to use them to the best of their capabilities.
- This topic is personally connected to me because of my major. I am a mechanical engineer and am currently enrolled in ME2110, the "robot building class". In this class to assist with our designs, we often used solenoids as deployment mechanism. Being able to learn about this topic while working with the objects hands on in a non-physics environment helped me immensely in my design process and physics career.
History
The history of inductance goes back quite a long time ago and is pretty complicated. In the early 19th century there were actually two scientist discovering inductance in parallel with each other, one in America and one in England. These two scientist names are Joseph Henry and Michael Faraday. Because of this there is no one named founder of inductance, but both of them did receive credit. Inductance now finds itself as one of Faraday's Laws, giving Michael Faraday his due credit. While the units for inductance are "Henries" named after Joseph Henry.
See also
Faraday's Law
Further reading
Information for this page was found in Matter and Interactions Volume II. If you would like to know more about this topic or other topics like it, please reference this book.
References
This section contains the the references you used while writing this page
[1] The Main Idea M S Smith 1967 Phys. Educ. 2 195