Electricity

Electricity is the term given to the set of phenomenon related to existence and movement of charged particles. The fundamental of electricity itself lies in charges, that can either be positive or negative. However, the type of charge itself depends on the presence of negatively charged subatomic entities (particles) called electrons, the absence of electrons depicting positive charge.

History

Benjamin Franklin is often credited with the discovery of electricity in the 1700s, with his kite experiment. He flew a kite with a metal key tied to it during a thunderstorm. However, the original discovery of static charge dates back to 600 BC when a Greek named Thales discovered that amber, when rubbed with silk, attracted feathers and other light objects. The Greek word for amber is 'ëelectron', which is the origin for the terms 'electron' and eventually 'electricity'.

In the early 1600s William Gilbert, a scientist and physician to Queen Elizabeth I, discovered the relationship between magnetism and electricity. He discovered Earth's magnetic field and also coined the term 'electricity'. In early 1700s, machines to generate static electricity were made for the first time and were called 'parlour trick machines'.

In 1705, Francis Hauksbee invented neon light while experimenting with mercury. The invention was a mistake, done unknowingly. It was not until 1752 that Benjamin Franklin, a popular politician in the USA flew a kite tied to a metal wire to light a lamp ultimately proving that lightning is indeed a form of electricity. In 1780, An Italian man named Luigi Galvani discovered that when he touched a dead frog's leg with a knife, it twitched violently. Later, Alessandro Volta showed that this was because electricity is created when moisture (from the frog) comes into contact with two different types of metal (the steel knife and a tin plate), then electricity is created.

Pile Volta in 1800, created the very first simple battery using pure silver and zinc discs, placed between muslin which was dampened with a salt solution. This was developed from Galvani's experiment with the frog's legs.

During the same year, Sir Humphry Davy discovered electrolysis. When he passed an electrical current through some substances, they'd begin to decompose. This became known as electrolysis. Davy's experiments later led to the discovery of a range of elements, including calcium, magnesium, strontium, and barium.

In 1820 Magnetic fields caused by electricity were discovered. Hans Christian Oersted, from Denmark, found that when electricity flows through a wire, it generates a magnetic field which affects the needle of a nearby compass. A year later in 1821, Michael Faraday discovered that when a magnet is moved inside the coil of a copper wire, a tiny electric current flows through the wire. This discovery led to the invention of electric motors.

In the same year, Thomas Johann Seebeck discovered thermo-electricity. He found that when the junctions of certain metals are heated, electricity flows through them. In 1827, a German college teacher named George Ohm published his paper on complete mathematical theory of electricity, which also has the mathematical prove for a law pertaining to the flow of electrons in conductors under certain given conditions, now named Ohm's law after him. Three years later in 1930, Joseph Henry an American scientist discovered the principles of dynamo - electrical generator. In April, 1931 Michael Faraday demonstrated electromagnetic induction by passing a magnet through a coil of wire. In the same year Charles Wheatstone and William Fothergill Cooke also created the first telegraph machine. Charles Wheatstone also succeeded in measuring the velocity of electricity on 1834. 

A British scientist named Joseph Swan in 1878 demonstrated the first electric light with a carbon filament lamp. Thomas Edison made the same discovery a few months later in America. In 1881, the first public electricity supply in the UK was generated in Godalming, Surrey, using a waterwheel at a mill. At this period of time, various inventions took place in the field of electricity and it's related applications such as the invention of the first electric hand drill in 1895 by Wilhelm Fein, in the same year Wilhelm Roentgen a German physicist discovered X-rays. In 1905, Albert Einstein, yet another German theoretical physicist discovered that light rays and hence radiation of any frequency in general could produce electricity, now known famously as the 'Photoelectric Effect'., for which he was later awarded Noble Prize. Solar panels are based on this effect of light.

Power Transmission

Power transmission is ususally done with very high voltage power lines, the load capacity of which may vary depending on the voltage of current it carries. In most parts of the world, lower from electricity generation stations is transmitted in 11K Volts and is later decreased for household consumption using powers transmission towers and houses.  

A typical power
transmission line in
India, carrying 11K
Volts