Many of the things you use in your home and at school uses electricity. We have come to not only rely on electricity, but expect that it is available whenever we need it. You know that when you open the refrigerator the food will be cold because it is plugged in. When you need to charge a cell phone, watch TV or even run your microwave, it is electricity that allows everything to work.
Electricity exists in nature in many forms. Lightning is an atmospheric electricity that discharges in the air. The speed of a lightning bolt can travel at 130,000 mph (320,000 kph) and can reach almost 54,000 degrees Fahrenheit (30,000 degrees Celsius)
Electricity exists in our bodies as it helps our hearts to beat. Heart muscle cells contract due to electricity. If you ever watched a television show where they had an electrocardiogram machine, you would see that someone who is healthy has a steady line and then a spike in the line when the electricity causes a heartbeat.
Electric eels have the ability to generate electricity within their body. They use it for hunting and defense and can send out a shock at 500 volts.
In America, Benjamin Franklin studied electricity in lightning in the 18th century. His research showed that the electricity from lightning can be attracted to certain materials and then discharge the electrical buildup. He invented the lightning rod as a way to protect buildings. The lightning rod allows the electricity to hit the rod and then go through the ground instead of hitting a building directly.
Electricity can build up in everyday situations. This is called ‘static’ electricity. You may have experienced it in dry weather when you walk across a carpet and then touch something metal. You get a small ‘shock’ that is a discharge.
- One of the rules of electricity is that it will always try to find the easiest path that it can towards the ground.
- Electricity is actually a type of current and the name of the type of measurement is amps (amperes)
- Electricity measured as potential energy is called ‘volts’.
When you have two ‘positive charges’, they will repel or push each other away. The same thing happens when you have two ‘negative charges’. But when you have a positive and a negative charge they will attract each other.
- Electricity occurs in what is called ‘electric fields’ and they can either attract or repulse. Gravity is similar except that it can only attract.
- Engineers control electricity through various mechanisms: transformers, switches, and resistors. These are used to allow the flow of electricity without overwhelming the wires and cables that it flows through.
If you didn’t have the mechanisms to control electricity, it would open up so much electricity that if you plugged something in it might make it explode. It would ‘overload’ the television or microwave.
There are two kinds of electricity: AC (alternating current) and DC (direct current). The main difference between the two of them is the manner in which the electrons flow. In AC, the electrons change directions, switching between forward and backwards. In DC, electrons move in one direction. An example of DC electricity is the type that comes from batteries, while AC is the electricity that is in your house.
Electricity can be produces using a number of what is called ‘renewable and sustainable’ ways. These are methods that can make use of existing power, such as wind, solar and water and create electricity without harming the environment.
The largest source of electrical energy today comes through the use of coal. The burning of coal boils water that turns to steam and then spins turbines that are connected to generators. Coal is not good for the environment as it creates pollution.