About Static Electricity

Static Electricity is a study of static electrical charges comprising of both positive and negative charges. The S. I. unit for static electrical charges is Coulomb, C. Static charges are produced on the surface of conductors and insulators of electricity. 

Detection of Static Electricity

Static charges is produced on the surface of electrical conductors by the process of induction. Whereas it is produced on the surface of electrical insulators by the process of friction. Static charges cannot be detected with our naked eyes but it can be detected by an electroscope.

Whether static electricity is produced by friction or induction, they abide by the followings... ...

• Like charges always repel each other 
• Unlike charges always attract each other
• There are two kind of charges, positive and negative

Hazards and applications of Static Electricity

Static electricity poses hazards which could endanger both our lives and properties, such as lightning, fire and explosion. On the other hand, it has as well many applications to our daily lives, like flue-ash removal, high-voltage generator and spray painting.

Hazards of Static Electricity - Lightning

Lightning is due to large quantity of electrical charges built up in heavy thunderclouds. The thunderclouds are charged by friction between water and air molecules. When the charges continue to build up to a very high level, it ionise the air and create a path to discharge large amount of charges to the nearest object near the ground. This explains why it is dangerous to play in an open field or swin in an open sea during thunderstorm.

Hazards of Static Electricity - Fire and Explosion

A fire and explosion may occur when excessive charges build up by friction. Examples are charges built up by aircraft and truck carrying flammable substances. To avoid this hazards, charges discharge path is essential. For the aircraft, the tyres are built using slightly conductive rubber to discharge massive amount of electrical charges built up during the landing. 

Applications of Static Electricity

Flue ash removal uses the rule of "Unlike charges always attract each other" to remove smoke and dust particles from the waste gas that flow through chimneys into the atmosphere. 

High voltage generator can produce a voltage of up to 14 million volts for nuclear researches and experiments.

Last but not least, electrostatic spray painting is an efficient way to create good adhesion of paint to every corner of the object uniformly economically.      

Copyright 2008