11. When lines of force are perpendicular to the sheet, the flakes are edge-on, and appear significantly darker. 12. Magnetic lines of force attract ferrous particles. 13. It looks like the lines of force in the figure at left are hand drawn and not calculated. 14. Sort of like lines of force . 15. James Clerk Maxwell drew attention to this fact in his 1861 paper " On Physical Lines of Force ". 16. One enigma concerns the lines of force of the earth's magnetic field, both today and in the distant past. 17. Historically, the first time fields were taken seriously was with Faraday's lines of force when describing the electric field. 18. The bombs released charged particles which behaved exactly as Christofilos had predicted, being trapped along the lines of force . 19. At zero degrees, the rectangular arm of the armature does not cut any lines of force , giving zero voltage output. 20. Electro propels himself along magnetic lines of force in objects that have great electrical potential, such as high-tension electrical lines.
