Solve the all parts of following question given below:

Question: A newly designed electric train is to be driven by the force on a conducting axle due to the vertical component of Earth's magnetic field. To produce the force, current is maintained down one rail, through the conducting wheel, through the horizontal axle, through another conducting wheel, and then back to the source via the other rail.

Part A: Sketch a diagram and explain how this design propels the train forward;

Part B: If the vertical component of the magnetic field is 10?T and the axle is 3.0m long, what current is needed to provide a (relatively small) force of 10 kN?

Part C: At what rate would electrical energy be lost per ohm of resistance in the rails?

Part D: Do you think such a train is realistic?
Why / why not?

I want you to explain the physics in this question.