Static electricity

• conductor: material that allow charge to flow through

  insulator: no free charges, does not allow the flow of charge through them.
• insulting materials rubbed against each other they become electrically charged
• gains electrons - negatively charged

  loses electrons - positively charged
• uses:

  photocopiers

  sprays
• photocopiers:

  image projected on positive charged plate

  plate loses charge in light areas

  negatively charged black toner applied

  toner transferred onto white paper

  heated.
• sprays:

  becomes positive as leaves spray

  droplets repel each other - cover large areas

  attracted to negative earth - fall quickly and not blown away
• dangers - sparking

  prevention method - earthing

  fuelling vehicles - friction between fuel and pipe can cause fuel to gain charge and could spark. fuel tank is connected to the earth. the conductor earths the plane by carrying charge to the earth.