- #1
SherlockOhms
- 310
- 0
Homework Statement
A copper wire of diameter d carries a current density at the Earth’s equator where the Earth’s magnetic field is horizontal, points north, and has magnitude 5.yz × 10^-5 T . The wire lies in a plane that is parallel to the surface of the Earth and is oriented in the east west direction. The density and resistivity of copper are ρm = 8.9 × 10^3 kg/m3 and ρ = 1.7 × 10^−8 Ω-m, respectively. (x,y and z are given constants).
(a) How large must J be, and which direction must it flow in order to levitate the wire? Use g= 9.81 m/s
.(b) When the wire is floating, how much power will be dissipated per cubic meter due to resistive heating in the wire?
Homework Equations
F = ILB (F = JALB = JVB.)
F = mg.
m = density(Volume)
So, F = density(volume)(g)
The Attempt at a Solution
JVB = density(V)(g)
cancel the V's and solve for J (Positive so it flows in the east direction?)
I think that's the correct way to do (a), please point out if I've made an error. I can't seem to find the relative equation for part (b). Any help would be great!