Equation 10 gives the magnetic field at the midpoint between two axially-aligned wire loops separated by a distance d. A Helmholtz coil has d=R where R is the loop radius. Use this fact to simplify Equation 10. You will use this to calculate the field strength in your Helmholtz coil during the experiment.
B₀​ = (μ₀​ NI/R)​ [1/ 1+(d/2R )²]³/²
where
μ₀​ =4π×10⁻⁷ H/m is the vacuum permeability
N is the number of turns in each loop (our setup has N=124)
I is the current passing through the coil
R is the loop radius
d is the separation between loops