2016 Feb

Introduction to Electricity

February 23, 2016


Mankind’s dependency on electricity has reached a point where an hour of power outage across the globe can throw the world into jeopardy. Just to get a picture of it, think of everything that runs on power, all forms of communication systems (internet, mobile and landline phone technology, television broadcasts), critical equipment in hospitals that run on power, control and guidance of air, land and sea traffic; these are just a very few of the umpteen number of sectors for which electricity is a lifeline.

Now the repercussions of a power outage would be stock market collapses, large number of deaths in hospitals owing to the failure of critical equipment, plane crashes across the globe, disruption of traffic, etc. This is the result of just an hour of power outage. Unimaginable it is to think of the chaos days long power outage would lead to. Given the importance of electricity in the current world, a series of articles is dedicated to electricity and its generation.

The term electricity is associated with or often encompasses aspects like electric charge, electric current, electric field, electric potential, which are terms we have learnt during our JC Physics tuition classes. The story of electricity dates back to times when the discovery of electric eels is recorded. Fish like electric eels biologically produce electric current that can be felt as a shock when touched. This is a defence mechanism in these organisms. This is the first recorded observation of electricity though mankind was familiar with thunderbolts for ages. These fish were named ‘thunder of Nile’ and it dates back to 2750 BC. When amber is rubbed with cat’s fur, it develops the ability to attract light objects. This phenomenon is because of something called as static electricity. Amber develops charge on it and a light object in the vicinity of it develops charge of the opposite type, since opposite charges attract each other the object gets attracted to it.

Electric current, which is different from static electricity, is the rate of movement of charge along a conductor. Our earlier articles describe how this motion of charge is initiated by electric potential difference. The concept of electric field and the nature of force at a distance were also discussed in great detail. Electromagnetism is a phenomenon where the motion of charge or time varying electric field generates magnetic field. The converse of this phenomenon is also observed. The potential of electricity was left untamed for thousands of years. The research in this field hardly had any immediate ramifications. Soon after the invention of various electric appliances electricity gained popularity and the era of electronics fortified the wave. It may now sound insane but Michael Faraday was once asked, “Why electricity is valuable?” and he answered the politician saying “ One day you may tax it”.

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