Figure 6
Magnetic force experiments are conducted by using a NdFeB permanent magnet and a nonmagnetic spring. Full magnetic-pulling power is exerted onto the small, medium, and large coils, respectively. The gray rectangle indicates the coil is off while the orange rectangle indicates the coil is turned on and at the maximum power. Powering all the coils at the maximum power yields 1.673 N pulling force as demonstrated on the right-most image.
