Get the Knowledge that sets you free...Science and Math for K8 to K12 students

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Electrostatic jellyfish Electrostatic jellyfish When a PVC pipe gets rubbed with a woolen cloth, it acquires electrostatic negative charge. The same type of charge is acquired by the packing string (that looks like a jelly fish), when it is rubbed with the woolen cloth. Therefore the same charge on both these bodies leads to repulsion which is a feast to observe.
Electricity from lightning As the lightning occurs, it can be captured using a three–foot bolts arranged in an order on a plane ground. Each of these three–foot bolt generates enough electricity to illuminate a 60–watt light bulb for 20 minutes. But a full–scale system could power 30,000 homes for a day with just one lightning bolt. It is believed that the average Midwest thunderstorm releases enough electrical energy to power the entire U.S. for 20 minutes. Who knows what the potential is for the harvesting of lightning fields and arrays of bolt conductors?

Electric charges are one of the fundamental building blocks of atoms. The atom′s massive central nucleus is positively charged, while lighter, negatively charged electrons orbit the nucleus. An object is negatively charged if its atoms possess either an excess of electrons or a deficit of electrons. The French physicist Charles Coulomb deduced that charge manifests itself in two opposing forms. Coulomb′s law describes forces between electric charges as: Like charges repel each other and opposite charges attract. The force between the charges is directly proportional to the product of the charges and inversely proportional to the distance between them. The study of electric fields created by stationary charges is called electrostatics.

Electric current is a movement or flow of electrically charged particles, the intensity of which is usually measured in amperes. The process by which electric current passes through a material is termed electrical conduction. Its nature varies with that of the charged particles and the material through which they are travelling. While the particles themselves can move quite slowly, sometimes with an average drift velocity only fractions of a millimeter per second, the electric field that drives them itself propagates at close to the speed of light, enabling electrical signals to pass rapidly along wires. Current is often described as being either direct current (DC) or alternating current (AC) depending on how the current varies in time.

The electric potential at any point is defined as the energy required to bring a unit test charge from an infinite distance slowly to that point. It is usually measured in volts, and one volt is the potential for which one joule of work must be expended to bring a charge of one coulomb from infinity. An electric circuit is an interconnection of electric components such that electric charge is made to flow along a closed path (a circuit), usually to perform some useful task. The components in an electric circuit can take many forms, which can include elements such as resistors, capacitors, switches, transformers and electronics. Ohm′s law is a basic law of circuit theory, stating that the current passing through a resistance is directly proportional to the potential difference across it.

Electrical power is highly versatile as a means of providing energy. Hence it finds use in a wide range of applications which include transport, heating, lighting, communications, and computation. Electrical power is usually generated by electro–mechanical generators driven by steam produced from fossil fuel combustion, or the heat released from nuclear reactions; or from other sources such as kinetic energy extracted from wind or flowing water. Environmental concerns with electricity generation have led to an increased focus on generation from renewable sources, in particular from wind, solar and hydropower.

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