Uses of static electricity

Spray painting

The nozzle of the spray gun is charged so the pain will have the same charge. The droplets repel to form a fine spray. The metal object will be oppositively charged so it will attract the paint droplets. This gives an even coat of paint and cover all parts of the object

Spraying insecticide

The nozzle is charged so the droplets are the same charge. The droplets repel each other giving a fine spray. Plants are charged by induction by the spray so the surface of the plant is oppositively charged and will attract the droplets. All plants will be coated evenly

Making sandpaper

Sandpaper is sprayed with glue which is charged. Sand particles are oppositively charged and are attracted to the glue. The particles repel each other forming an even layer on the sandpaper

Photocopier

Image is projected onto a charged copying plate. The light in the image causes the charge to leak away where light is the brightest. Oppositively charged toner particles are attracted to areas that are the opposite charge. The copying plate is pressed against the paper so toner is transferred to paper

Electrostatic precipitator

Smoke particles rise upwards and become charge when they touch the grid. They are attracted to the oppositively charged collecting plate where they will lose their original charge. They then fall downwards where it's collected

Laser printer

Drum is charged. A laser shines on the places which will appear black and this make the drum loses its charge in those places. When the drum passes over the toner which is the same charge it only sticks to the part which are neutral. The drum then rolls against the paper and the toner is transferred to it

Defibrillator

Two paddles have charged insulated paddles with a high voltage. One paddle is negative and the other positive. The charge cause a current to flow through the patient making the heart contract

Cling film

As it unwinds electrons are transferred from one layer to another to give areas of positive and negative charge. It will repel electrons near the surface of a bowl and attract the opposite charge