Electricity - العلم نور


الجمعة، 22 مارس 2019



         We can easily say that electricity is produced when any matter carrying electric charge moves. An electric field is produced when either positive or negative electric charge is present. In the beginning, scientists considered that there is no relation between electricity and magnetism, but after that they discovered that the electric current which is generated by the movement of electric charges produces a magnetic field. In this article, we will know more about electricity which is on of the most important physical phenomena used in everyday life.

Important concepts related to electricity

§  Electric charge
         Electric charge which is carried by either electron or proton can be measured by the gold-leaf electroscope. It's measured in coulombs and takes the symbol Q. this electric charge may be positive as in the case of proton or negative as in the case of electron. These electric charges exert a force on each other. So, these charges repel if they are similar to each other and attract if they are in two opposite forms.

§  Electric current
         It's measured in Amperes and takes the symbol I. it's produced by the movement of electric charge. These electric charges are electrons in most cases. Electric current is conventionally considered to move from the positive part to the negative part through the electrical conductors. Electric current is classified into direct current (DC) and alternating current (AC). Direct current is used in electronic devices mostly and can be produced by a battery. Alternating current is used in our homes which reverses direction repeatedly and has a time-averaged value of zero.

§  Electric field
         The electric field was introduced by Michael Faraday. An electric field is created by one body having a charge in the space that surrounds this charged body. The resulting force will affect any charge exist within the produced electric field.

§  Electric potential
         It's defined as the energy required to move a unit charge from an infinite distance to any specific point within an electric field. Electric potential is measured in volts and takes the symbol V. the electric potential difference is defined as the energy required to move a unit charge between two points.

§  Electrochemistry
         It's considered as an important branch of electricity. It's the production of electricity by using chemical reactions, and also the usage of electricity to drive chemical reactions. it's used widely in too much applications.

Electricity production
         The most famous method which used to generate electrical power is the use of electro-mechanical generators which are driven by steam. It can also be generated by extracting the kinetic energy from the flowing water or from the wind. Today, most of the electricity is produced by the modern steam turbine which was invented in 1884.

Electricity Applications
ü One of the most important applications of electricity is the light bulb which invented in 1870 and led to lighting.
ü Electricity is used in heating applications such as heat pumps and cooling applications such as air conditioning.
ü Electricity was used in telecommunication applications such as electrical telegraph.
ü Electricity is used in public transportation for the production of electric motor.
ü Electricity is used widely in electronic devices for the production of transistors.

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