Helmholtz Coil Field at Center
A Helmholtz coil is a device for producing a region of nearly uniform magnetic field. It consists of two solenoid electromagnets on the same axis.
The magnetic flux density is proportional to the current times the number of coils divided by the radius.
Formula
![Copy to Clipboard QuantityVariable["B", "MagneticFluxDensity"] == (Quantity[8/(5*Sqrt[5]), "MagneticConstant"]*QuantityVariable["I", "ElectricCurrent"]*QuantityVariable["N", "Unitless"])/QuantityVariable["R", "Radius"]](https://www.wolframcloud.com/objects/resourcesystem/marketplacestorage/resources/d90/d90d7fe2-55b7-4f55-bbc3-56a0a418a5a0/Webpage/FormulaImage.png)
| symbol | description | physical quantity | 
|---|---|---|
| B | magnetic flux density | "MagneticFluxDensity" | 
| I | electric current | "ElectricCurrent" | 
| N | coil turns | "Unitless" | 
| R | radius | "Radius" | 
Forms
Examples
Get the resource:
| In[1]:= | ![ResourceObject["Helmholtz Coil Field at Center"]](images/d90/d90d7fe2-55b7-4f55-bbc3-56a0a418a5a0-io-1-i.en.gif) | 
| Out[1]= |  | 
Get the formula:
| In[2]:= | ![FormulaData[ResourceObject["Helmholtz Coil Field at Center"]]](images/d90/d90d7fe2-55b7-4f55-bbc3-56a0a418a5a0-io-2-i.en.gif) | 
| Out[2]= |  | 
Use some values:
| In[3]:= | ![FormulaData[
 ResourceObject[
  "Helmholtz Coil Field at Center"], {QuantityVariable[
   "B","MagneticFluxDensity"] -> Quantity[900, "Nanoteslas"], 
  QuantityVariable["N","Unitless"] -> 1}]](images/d90/d90d7fe2-55b7-4f55-bbc3-56a0a418a5a0-io-3-i.en.gif) | 
| Out[3]= |  | 
 
                 
                