Electric Energy
One of the forms of energy that we use everyday is electric energy. This type of energy is made possible for use through the flow of electricity or an electric charge through a conductor. The electric charge comes from objects with charged particles. It is a characteristic or a property of the object. Sometimes touching two things together can cause one of them to become charged or the particles of the object become charged.
Electric energy can be formed by transforming other forms of energy, like solar energy, wind energy, water energy, or thermal energy. Once electric energy is present, this can be transferred by an electric circuit and turned into electric power, what we know as electricity. Once electricity is flowing, it uses its power to transfer energy into other forms of energy. For example, electric power turns into mechanical energy which runs our toasters. It can also turn into heat energy which boils water, or it can turn into light energy and power our bulbs in order to give us light.
A basic electric circuit is what turns electric energy into electric power. The basic circuit consists of a source of electric energy (charged particles), conductors connected to the source and then connected to a load or a device that is powered by electricity. In every electric circuit there is a positive charge and a negative charge. This is needed because the charged particles go from the negative connector (known as a terminal) of the source and pass through the load, going back into the positive terminal. Known as a direct current, this circular motion of electricity is your basic electric circuit. This basic concept can be demonstrated by creating a battery out of a lemon.
A Lemon Battery
Materials:
LED (Light Emitting Diode)
6 copper pennies
6 galvanized nails (zinc coated nails)
6 small jumper cables with alligator clips
6 lemons
Small knife
Instructions:
1. Take each of your lemons and roll them onto a table with your hand, gently pressing down on the lemons as you roll them.
2. Stick one galvanized nail into each of your lemons. Make sure you stick the nail near one end of the lemon.
3. Next, with a knife, make a small incision on each of your lemons. This incision should be on the other end, opposite the nail, and large enough for you to stick the copper penny into.
4. Using your jumper cables, clip a copper penny of one lemon onto the nail of another lemon. Connect the copper penny of the next lemon to the nail of another lemon. Continue in this process till you have one free penny and one free nail.
5. Attach the 5th jumper cable to the free nail and the other jumper cable to the free penny. This means you have two free alligator clips, with one connected to a penny and another connected to the nail.
6. Take the alligator clip attached to the nail and connect it to the flat wire of the LED. The other alligator clip attached to the penny should go onto your rounded LED wire. What happens to the LED?
Batteries can be created by suspending two different metals in an acid. Lemons are a citric fruit and contain citric acid. The nail is made of zinc, while the penny is copper, these two different metals create a positive and negative charge in your lemon, which is what you need for a basic circuit. A single lemon cannot power the LED and that is why you use several, connecting the positive charge from each battery into the negative charge of the other until you are left with one free positive charge and one free negative charge to connect to your LED. The electric current runs through the series from negative to positive, powering the LED.
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