关键词: 电流密度, 剩磁, 力矩, 运动半径 

Abstract:
On the basis of existing experiments, we improve the experimental device and analyzed the influence on magnets that was exerted by the current flow direction and the temperature. Meanwhile, we have observed the cylindrical battery and the homo-polar roller which was composed by the button magnets (permanent magnets) absorbed at both ends. It is found that when the homo-pole roller is placed on the aluminum foil, the magnets with same or different radii at both ends lead to disparate movement phenomena, respectively. We analyze the roller’s moving course on the foundation of simplified dynamics theory and obtained the relationship between the displacement and time with the same radius as well as the relationship between the magnet radius and the magnet moving radius with different radius by combining the simulation and experiment. 

Key words: current density, remanence, torque, motion radius