One way to increase the efficiency of a generator is to increase the strength of the magnets applying a force perpendicular to the wire. But what about the other way? Instead of making the magnets stronger, what kinds of metals are more sensitive to magnetic force? And what is this property called? Is the ability for a metal to be able to generate a current through it's susceptibility to magnetic fields different than its conductivity? Or can I just assume silver is the best metal for this whole process? Is there anything more conductive than silver, besides like graphene maybe? Also how do you explain this property? Silver has more/less...force holding metallic bonds together, allowing electrons to move more easily?
1 Answer
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It is true that the lower the resistance per unit length of the wire in coil of the generator the lower the loss of energy due to heating in the coil.
This resistance per unit length with unit cross sectional area of wire is called the resistivity of the material,$\rho$. Also: $$\rho=\frac{RA}{l}$$
The difference in such conductivity of silver and copper is very minimal compared to their costs. Silver is only about 5% a better conductor than Copper, while its cost is many times more. So realistically we don't use silver wires in generators as the increase in costs outweighs the decrease in costs due to lower energy losses. And in generators it's far more effective to use money to help reduce other factors of energy loss like from friction, eddy currents in iron core(which coil is wound about) etc. which contribute higher energy losses.
Also, the reason silver is a slightly better conductor than copper is due to silver's electrons in its sea of electrons being at a larger distance away from the nucleus so they feel less attraction than in copper( of course there are other complicated explanations related to orbitals which I'll leave out here).
answered Jun 25, 2017 at 7:05