1. The problem statement, all variables and given/known data Suppose you are stranded on an island and need to make a radio so that you can get weather updates. You know that weather updates for your general area can be found on short-wave radio within the frequency range f-low to f-high . Also, you manage to scavenge some thin, insulated wire of thickness d, of which you can allocate a length l to make a solenoid inductor. You also manage to find a long plastic tube of length a and diameter D, a large roll of foil of width w, a large mylar sheet of thickness 1/100d and dielectric constant κ=3 that will accommodate the area of the foil, a speaker from headphones with impedance R, and a small transistor. Being extra resourceful, you manage to make a small battery out of a lemon, a galvanized nail, and a nickel that you attach to the transistor and headphone speaker to amplify the radio signal. Part A: Assuming that you use the entire length l of wire for the inductor, as well as the plastic tube as a form, what is the maximum inductance achievable? 2. Relevant equations Part A: L=NΦ/i Where N is the number of turns, Φ is the magnetic field flux, and i is the instantaneous current provided by the battery and transistor. Φ = (A)(B) 3. The attempt at a solution The answers are all variables. I assumed N=1. I broke down A and B into (πr^2)(Nµi/2R) which when plugged into the equation for L cancels out i, which was promising as none of the answer choices had i. The issue I'm coming up with is what to consider r for the area, and R for the magnetic field. Maybe the question's wording is confusing me but I don't know what to do with the insulated wire of thickness d and length l, and the long plastic tube of length a and diameter D. Thanks for anyone who even read this.