Current density of copper

Answer 1

The amperage rating of a copper wire is related to its resistance and to the type of insulation used (i.e., what temperature the insulation can handle) and the ambient temperature. The fatter the copper wire, the more amps it can handle, everything else being equal. A mineral-insulated wire, buried underground, would handle more amps than a similarly sized copper wire in thermoplastic insulation in air.

There are electrician charts available to determine the MINIMUM size of copper (or aluminum) wire necessary for a particular load.

Consider also that longer the wire, the more resistance there is, so a very long wire would need to be larger to handle the same load safely.

Answer 2

Magnetic flux density is the amount of flux goes through a unit area. The flux density depends on the magnetizing current through the conductor.

B = μ H; (B - Flux density , H - Mag. field, μ-permeability)

Further B ∝ flux , H ∝ i

By studying BH loop you'll get an idea about the relationship (that after some H, the flux is saturated)

* The question must be changed as what's the permeabilityof Copper..... (I guess)

Only the permeabilty is a constant for a material given, here Copper. It's 1.2566290×10-6 H/m.

Answer 3

if you know the number of amperes and the cross sectional area you can find the current density