# Does the coil's winding material matter?

Imagine you've got two coils with exactly the same cores, but one winding is made of material with its density different from the density of winding material of the other coil.

Would that configuration make differences in these two coils properties? Or maybe only the amperage matters?

What other things describe coils' windings?

• What exactly do you mean by "winding material"? Are you talking about the wire itself, or something else? – Dave Tweed Jan 15 '15 at 16:50
• @DaveTweed Yes, I mean the wire itself. – Gabrijel Šimunović Jan 15 '15 at 16:52
• Huh? Different wire materials will have different resistances, it's not really the density, but the conductivity. – George Herold Jan 15 '15 at 16:56
• The coil with denser wire will be heavier. Is that the sort of thing you're looking for? The electrical properties only depend on the geometry of the coil and the resistivity of the wire. – Dave Tweed Jan 15 '15 at 16:56
• The magnetic reluctance and dielectric properties of the wire's insulation will also affect the coil. – Samuel Jan 15 '15 at 17:22

The magnetic flux B of a solenoid with one layer of windings is expressed as:

• μ: Magnetic properties of the core
• N: Number of turns
• l: Length of the coil
• I: Current through coil

μ is constant (at least in theory), coil resistance has no part in this equation, and all other parameters in the equation remain the same as you state, except for the current I.

The magnetic flux is therefore only proportional to the current flowing through the coil.

Nevertheless, a higher specific resistance of the conductor material results in a higher overall coil resistance, which in turn requires a higher voltage over the coil's terminals to produce the same amount of current.

Although the flux B for other coil configurations is expressed differently, resistance has never a part in it.

There is also no correlation between material density and electric resistance.

• +1 because increase of electric field increase the power dissipation (σ*Ε^2*volume of wire) and consiquently the temperature rise of coil, making this totally useless. So there is no difference between two coils(!?) – GR Tech Jan 15 '15 at 19:42

Officially, material density it is expressed in kg/m3. The higher the density of the conductor, the lower the resistivity, the higher the current flow per unit area.

Since a coil magnetic field strength it is proportional of N·I (ampere-turns), the higher the current passing through the same number of turns, the stronger the magnetic field strength.

A typical example is two coils constructed using one with aluminium and the other with copper wire.

Check by yourself the density and resistivity of this materials.

• What's a Kgr? And does higher density really mean rower resistivity? That would mean that lead is a better conductor than copper, and osmium is the best conductor, I guess. Is it really? – Phil Frost Jan 15 '15 at 18:10
• -1 as Phil says density does not relate to resistivity. – George Herold Jan 15 '15 at 18:18
• @PhilFrost Frost Kgr is kilogram, and before you dress your ironic costume, please look at the resistivity tables then downvote massivelly. Copper 1.68x10^-8 Ωm, Lead 22x10^-8 Ωm. – GR Tech Jan 15 '15 at 18:18
• @GRTech Density and resistivity are unrelated physical properties. Silver is more dense than copper, but it has a lower resistivity. Similarly, Aluminum is less dense than copper but has a higher resistivity. However, gold is more dense than copper but has a higher resistivity. – helloworld922 Jan 15 '15 at 19:05
• @GRTech it's highly advisable to use a dash in that case. – Nick T Jan 15 '15 at 19:59