Explain why a match-stick rubbed at one end with soap starts moving immediately in one direction when placed on the surface of water

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )

the higher the current the higher the mag field around it the higher the influence on the compass

i think its c if i'm wrong