Why does the light in your bedroom turn on when you flip a switch? How does a remote controlled car move? And how do the blinking lights on your TV and microwave work, anyway? The technology in your house may seem magical, but most of it wouldn’t run without electricity. So there is something that charges (the products that we see or use every day) or provides them a source to function. That source is called Electricity or Power. Life would be terrible if there was no power or electricity. I suppose no one would disagree with my last point.
Electricity is one of the newest or latest technologies, probably a few hundred years before only. That’s a late innovation when compared to history of man on earth. But it has become the most versatile and pioneer for every other technology or product that we see today.
You see electricity everywhere whether it is home, car, gadgets, office, school, shopping malls etc. But what is it and where does it come from? And why is the world today so obsessed with electricity. Can we not live without it?
What is Electricity?
Electricity is a type of energy that can build up in one place or flow from one place to another. The energy that is needed to produce the electricity comes from secondary sources like coal, petroleum, nuclear power etc. The primary sources are water, lightning, solar and wind.
In order to understand how electric charge moves from one atom to another, we need to know something about Atoms. Everything in the universe is made of atoms—every star, every tree, every animal. The human body is made of atoms. Air and water are, too. Atoms are the building blocks of the universe. Atoms are so small that millions of them would fit on the head of a pin.
Inside the Atom are even smaller objects called Electrons, Protons, and Neutrons. Electrons have a negative charge (-) and the Protons have a positive charge (+). The Protons and Neutrons stick to together in the center of the atom, called the Nucleus. The Electrons spin fast around the outside. The positive charge of the Protons keeps the electrons from flying off and leaving the atom.
The Electrons in the atom are where electricity gets its name. In some elements, there are electrons on the outside of the atom that, when a force is applied, can come loose and move to another atom. When a bunch of atoms are together and electrons are moving from one atom to the other in the same direction, this is called electricity. Electricity is the “flow” of electrons.
Now let’s see some of the parameters of Electricity:-
You must have heard these names in any electronic or electrical devices like 220V or 12V. Voltage is an electric pressure or force that causes free electrons to move from one atom to another.
Just like water needs pressure to force it through a hose, electrical current needs some force to make it flow. A volt is the measure of electric pressure. Voltage is usually supplied by a battery or a generator.
The measurement of voltage is called volts, and the scientific symbol is the letter “V.”
Current is electricity in motion. It measures the amount of electrons that can flow through a material like a conductor. Electrical current is measured in amperes or “amps” for short. Amps are similar to the amount of water flowing through a hose in a certain amount of time. Instead, it is the amount of electricity flowing through a wire.
The scientific symbol for amps is the letter “I.”
When current flows through a conductor it creates heat because of resistance. Resistance is how tight the material is holding the electrons. You may notice that a cord from an appliance feels warm after running for a long time – that is the amperage flowing in the circuit. The more amps moving, the more heat produced. When a wire carries too many amps for its size, it becomes “overloaded” and the insulation can melt and cause a fire or shock you if you touch it. That’s why it is important to have the correct wire size.
The measurement of resistance is called ohms, and the scientific symbol is the letter “R.”
- Power (P)
The work performed by an electrical current is called Power. The unit of Power is the Watt.
The part of the circuit which performs work (e.g. a motor, a light bulb or a LED, etc.) is called Load.
There are two main types of current in our world. One is Direct current (DC) which is a constant stream of charges in one direction. The other is Alternating current (AC) that is a stream of charges that reverses direction.
1. Direct current (DC)
All electric currents are either direct (DC) or alternating (AC), depending on the source. Direct current always flows in the same direction. It is produced by batteries and DC generators.
Your parent’s car operates on direct current (DC). Your iPod and watch also use direct current (DC). Just about anything that is battery-operated uses DC.
2. Alternating current (AC)
Alternating current, or AC electricity, is the type of electricity you will find in your home or at school. Every time you plug something into a power point, you are using alternating current.
Alternating current (AC) regularly reverses its direction of flow, like a game of bullrush. It is produced by AC generators. Many things such as a laptop or a portable stereo are able to use both types of electricity. When they are plugged into a power socket they are using Alternating Current (AC). When they are running on their internal battery they are using Direct Current (DC).
Alternating Current (AC) has many advantages over Direct Current (DC). The main advantage is that it can be delivered easily and efficiently. Every time you flick on a light switch or plug in a toaster, alternating current is there to make your day easier.
How do we make electrons move to make electricity?
We make electricity by creating an electric circuit. In the case where you are turning on a light in your house: when you flip the switch “on” you are completing the electric circuit and causing electricity and electrons to flow through the light bulb.
For example, a simple circuit as shown above may include two components: a battery and a lamp. The circuit allows current to flow from the battery to the lamp, through the lamp, then back to the battery. Thus, the circuit forms a complete loop. All circuits can be distilled down to three basic elements:
- Voltage source:A voltage source causes current to flow like a battery, for instance.
- Load:The load consumes power; it represents the actual work done by the circuit. Without the load, there’s not much point in having a circuit.
- Conductive path:The conductive path provides a route through which current flows. This route begins at the voltage source, travels through the load, and then returns to the voltage source. This path must form a loop from the negative side of the voltage source to the positive side of the voltage source.
A Simple electric circuit and its parameters
An Electric circuit is a path in which electrons from a voltage or current source flow.
The point where those electrons enter an electrical circuit is called the “source” of electrons. The point where the electrons leave an electrical circuit is called the “return” or “earth ground”. The exit point is called the “return” because electrons always end up at the source when they complete the path of an electrical circuit.
For an electric current to happen, there must be a Circuit. A circuit is a closed path or loop around which an electric current flows. A circuit is usually made by linking electrical components together with pieces of wire cable. A closed path means that the circuit through the switch is connected. Current flows from the positive side of the power source (for example, the battery) to the loads wired into the circuit and back to the negative side of the power source.
A simple circuit
A simple circuit is just what it sounds like. A simple circuit! It must have an energy source such as a battery. It must be connected through a wire or a similar substance that will conduct electricity. It must also have a load or device, something that is going to be operated by the electricity. Once all these are connected, there is a simple circuit.
To try this for yourself, you will need a battery, two small lengths of wire and a light bulb.
Connect one end of the wire to the bottom of your battery. Connect the other end to the bottom of your light bulb. Connect the other wire to the top of your battery and the other end to your light bulb. Your circuit should now be complete and your bulb should be glowing.
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