The sixth electrical source in the series is Electrostatic. It is the oldest of all. This discovery happened over 2,600 years ago around 600 BC. The Greeks did not know they had discovered static electricity, but they observed that rubbing fossilized tree resin, or amber, with animal fur made the resin attract dried grass.
Although charge exchange happens whenever any two surfaces contact and separate, the effects of charge exchange are usually only noticed when at least one of the surfaces has a high resistance to electrical flow. This is because the charges that transfer to or from the highly resistive surface are more or less trapped there for a long enough time for their effects to be observed. These charges then remain on the object until they either bleed off to ground or are quickly neutralized by a discharge: e.g., the familiar phenomenon of a static 'shock' is caused by the neutralization of charge built up in the body from contact with insulated surfaces
Magic Tape Electrostatic Experiments
Historically electrostatic experiments and demonstrations have been problematic depending upon the relative humidity. When the humidity is high they tend to fail because the charges leak away quickly through the film of moisture that tends to form on the surfaces. It was discovered that the very good insulating properties of Scotch Magic Tape (TM) lends itself to some very nice electrostatic demonstrations.
Material needed. A roll of Transparent Tape. Chick HERE for information about Transparent Tape.
Experiment 1.
1. Pull out a 4 inch of tape from the dispenser.
2. Fold over about 1/2 inch of tape on itself forming a non-sticky handle.
3. Place the tape, sticky side down on a wood table. Smooth it out.
4. Prepare several small bits of paper and place them on the table.
5. Rub the surface of the tape with your fingers several times.
6. Grab the non-sticky handle and pull the tape up from the table.
. Hold the non-sticky tape side close and above the bits of the paper. What happens?
Experiment 2
1. Prepare a second piece of tape and place both tapes on the table.
2. Rub both tapes.
3. Pull up both tapes, one in each hand
4. Hold the tapes non-sticky sides close to each other. What happens? (Like charges repel)
Experiment 3
1. Place one of the tapes on the table sticky side down and rub it with your fingers.
2. Place the second tape on top of the first tape and rub it.
3. Grab the bottom tape and pull both up from the table.
4. Pull the tapes apart.
5. What happens when you hold the tapes near each other. What happens? (Unlike charges attract.
Experiment 4 (Positive Charge Generator)
1. Place on tape on the table and rub it.
2. Place the second tape on top of the first tape and rub it.
3. Pull up the top tape only. It is positively charged. This procedure will be used to trigger the Josh's Electrical Sources: Electrostatic demonstrator at GC61PCX.
Electrostatics
There are many examples of electrostatic phenomena, from those as simple as the attraction of the plastic wrap to your hand after you remove it from a package, and the attraction of paper to a charged scale, to the apparently spontaneous explosion of grain silos, the damage of electronic components during manufacturing, and the operation of photocopiers. Electrostatics involves the buildup of charge on the surface of objects due to contact with other surfaces.
The ability of opposite charges in static electricity is what's used when designing applications for it.
Dust removal: There are some appliances that can eliminate dust from the air, like air purifiers. They use static electricity to alter the charges in the dust particles so that they stick to a plate or filter of the purifier that has an opposite charge as that of the dust (opposite charges attract each other).
This effect is also used in industrial smokestacks to reduce the pollution that they generate, altough they work in a very large scale, the effect is basically the same as the home air purifier.
Photocopy: Copy machines use static to make ink get attracted to the areas where we need the information copied. It uses the charges to apply the ink only in the areas where the paper to be copied is darker (usually this means text or other information) and not where the paper is white, this process is called xerography.
Car painting: To make sure a car's paint is uniform and that it will resist the high speeds and weather to protect the car's metal interior, it is applied with a static charge. The metal body of the car is submerged in a substance that charges it positively, and the paint is charged negatively with the paint sprayer.
This process ensures a uniform layer of paint, since when there is enough negative paint in the car the extra will be repelled by the paint already in the car.
It also ensures that the paint won't fall off, since the electrical attraction between the paint and the car is stronger than if it was just sprayed.
* From http://hubpages.com/