1. The problem statement, all variables and given/known data In a lab that I did in Physics we calculated the magnetic field of a solenoid while constantly increasing the number of time the wire was wrapped around the electromagnet. After I obtained all the values, plotted it in a graph and found the line of best fit, the slope came out to be 0.0027*10^-3. I learned that the slope in an N vs. B graph is the permeability of free space multiplied by the current. The current was set to one and I made sure with an Ammeter. I am concerned that my calculated value of the permeability of free space is more than double of the actual constant, 4*pi*10^-6. 2. Relevant equations B = 0.0027*10^-3N + 0.0906 3. The attempt at a solution I tried justifying with the sensor picking up the magnetic field of the Earth as well, or magnetization of the solenoid but I can't seem to be obtaining the right justification.