Consider the possibility of a new design for an electric train. The engine is driven by the force on a conducting axle due to the vertical component of Earth's magnetic field. Current is down one rail, through a conducting wheel, through the axle, through another conducting wheel, and then back to the source via the other rail.
(a) Determine what current is needed to provide a modest 5 kN force? Take the vertical component of Earth's field to be 10 µT and the length of the axle to be 3.0 meter.
A
(b) Determine how much power would be lost for each ohm of resistance in the rails?
W