Hi, scientists!
How are you? In the last post I published what is an electromagnet, but I didn't explain what are the effects of electric current and it is necesary. There are three effects that the flow of electrons through conductive materials (electric current) produces:
- Heat
- Light
- Electromagnetism
What is electromagnetism?
When the electric circuit closes, it is transformed into a magnet and a magnetic field it's produced. There are two principles that are the basis of electromagnetism:
- All electric currents create magnetic fields (Oersted's experiment explains it).
- A changing magnetic field can produce an electric current (Faraday's experiment explains it).
An electromagnetic mechanism is any appliance that can use electromagnetic fields to produce electricity or convert it into mechanical energy:
1. Electromagnetic generators (transform mechanical energy into electricity):
- Dynamos consist of a magnet, inside which there is a coil ending in two separate semicircular conductors known as the commutator. The coil starts to spin, using an exeternal energy source, and an electric current is produced inside. They produce direct current.
- Alternators are similar to dynamos. The difference is that the collector is made up of two rings and each ring is in contact with a brush. They produce alternating current.
A motor is a device that can transform electric energy into movement. It works on the principles of attraction and repulsion and they are similar to dynamos, although they work in the opposite way.
Transformers
We use transformers to increase or reduce the alternating voltage. They consist of two copper coils. If we apply an alternating voltage to one of them, it induces a different votage in the other coil so we can transport electric energy at high levels of voltage without losing too much energy.
That's all. I wish it can help you to do some experiments at Technology lessons or if you are bored at home and you want to do some circuits. ;)
