A. This question has two parts. The first part involves amperes law concerning the strength of an electromagnet as measured in Tesla. Amperes law states that the strength of the B field of the strength of the electromagnet is determined by ampere turns and current in said turns known as MMF.
Yet amperes law is based on the permeability of the wire used for said ampere turns of one. What if we used a permeability of 1000 times that (iron). Wouldn't the magnetic field of the current be amplified for each turn of an electromagnet if a high permeability wire were used instead? Would that not increase the strength of the electromagnet by thousand fold?
B. If an electromagnet has a core made up of ten individual iron wires, each insulated from the other, but part of the same magnetic circuit with parallel reluctance, wouldn't each wire magnetize, and seeing how magnetic fields are cumulative, would this not create a stronger total Flux than one core of equal cross area? If a single core of same cross area had 0.1 Tesla but with the core with ten iron wires and each magnetic field is cumulative, it's total field strength would be 0.1 Tesla x10? The core with 10 wires all have the same 90 degree winding around all ten so to each wire it appears the same ampere turns or MMF.
Best Answer
Iron is a poor conductor compared to copper so making an electromagnet from iron wire is off to a bad start. Next, an electromagnet has basically a massive air gap and this is the bit that attracts i.e. the working end of an electromagnet is the air gap. This is generally why the attractive force produced by a solenoid electromagnet has nothing to do with the permeability of the core: -
Force = \$(N\cdot I)^2\cdot 4\pi 10^{-7}\cdot \dfrac{A}{2g^2}\$