PHYS 250 - Group 5 - Project 2

3 that you are trying to calculate the magnetic field of. According to the Minnesota Electric Transmission Planning website, for a transmission tower that is carrying approximately 200 kV , the average tower height is between 70 and 90 feet tall. Although this height may change depending on the regulations for the area that the “person” is located who would be standing under the wire, an estimate of 80 feet will be used for our calculations. The next variable that must be considered is the current that the wire will be carrying, which is a given amount of 10,000 A from the question that is trying to be solved. In the calculation, meters will be used instead of feet, so the distance of 80 feet will be converted to meters through the equation 1 foot = 0.3048 meters→ 80 feet = 24.38 meters . Once these variables are determined, it is just a simple matter of plugging them into the equation that was discussed previously in which B = μ 0 I 2 π d . Putting these values in accordingly results in the equation B = ( 4 π ⋅ 10 − 7 )( 10000 ) 2 π ( 24.38 ) , and gives the final value of 820.34 ⋅ 10 − 7 T for the magnetic field at this distance. It may seem like a relatively easy solution to a question like this, however with a Fermi question being a “back of the envelope calculation”, this is precisely the sort of ease that it should be calculated with. Conclusion In summary, we were given the example of a two-wire power line with 10,000 A and 200,000 V . We found the magnetic field was found to be 820.34 ⋅ 10 − 7 T for our final value. Biot- Savart’s and Ampere’s laws were used to find the value. It's important to identify all the correct variables needed to find the equation and identify the correct equation to use as well which for