Oh, electricity is not there. How will I watch television now? How will I microwave food? How will I switch on the air conditioner? I will have to bear the heat. How will I charge my laptop to play games? It is a very familiar situation, right? Electricity has become the most integral part of our lives now. Its difficult to imagine doing anything without it. It governs everything right from big machines in factories, to smaller household appliances. Even projectors, computers, generators and waste management systems at workplaces need electricity. We can’t do without it anymore. But what is electricity? how does it work?
Electricity is nothing but electric current. Current is defined as flow or movement of charged particles through a conducting medium. Conducting medium is the one which allows charged particles to flow through it, like cross section of a wire. The atoms of these conducting materials have lots of free electrons (negatively charged particles) surrounding them and these electrons keep moving in random directions. When we apply voltage or potential difference to these atoms, all electrons start moving in a same direction. This is what we call electric current. So, current produced by the movement of electrons is called electric current. For example, electric current in a mixer does not refer to movement of electrons in foods or vegetables. It refers to the movement of electrons through the heating element which operates the mixer.
UNIT OF MEASUREMENT
The SI unit of electric current is Ampere (A). One ampere is defined as the amount of electric current required when two straight parallel conductors of infinite length, of negligible cross-sectional area, are placed one meter apart in vacuum, to produce a force of 2*10-7 Newton per meter of length.
TYPES OF ELECTRIC CURRENT
- DIRECT CURRENT – In direct current(DC), the direction of movement of electrons is static. For example, in batteries, where electrons always move from negatively charged pole to positively charged pole.
- ALTERNATING CURRENT – In alternating current (AC), the direction of movement of electrons changes many times per second. AC is generally used to send power efficiently over larger distances, because of its ability to produce current at stabilized voltages. The electricity we use at home, the electricity produced by generators, are the examples of Alternating current.
Thus, the most prevalent day-to-day applications of electricity have a lot of science behind their functioning.