A thin rectangular aluminium plate of resistance 0.020Ω moves with a steady speed of 2.0m s−1 completely inside a uniform magnetic field of 1.2T directed perpendicular to its plane. The effective width of the plate in the direction of motion is 0.30m. Assume the eddy current paths may be treated as a single loop of this width.
(i) Calculate the magnitude of the motional emf generated around the effective loop.
(ii) Determine the current produced in the plate and hence the electrical power dissipated as heat.
(iii) Find the magnitude of the magnetic force opposing the motion of the plate.
(iv) For a time interval of 4.0s, compute the mechanical work that must be done to keep the plate moving at the given speed and compare it with the electrical energy dissipated in the same time.