"Do not go into the outlet - it can shock and kill!" - this is the phrase that haunts many people since childhood. But is it? And if so, why is the mysterious physical quantity - tension - still mentioned. And to understand all the concepts and dangers associated with electrics, you should look deep into the phenomena.
What is voltage?
Voltage is the potential difference. This is how physics textbooks are written for the 6th grade. But does everything become clear from such a phrase? Not at all ...
To best understand what stress is, consider a clear example. There is a metal, cast iron or plastic pipe, the inner diameter of which does not matter at all. At the beginning of this pipe, a pump is installed that creates a certain pressure in the system. Because of this very pressure, water moves through the pipe.
So that's it. The pressure in the system is the very same potential difference. If you remove it, then the water stream will not make any movement. But you can close the pipe on the other side and still apply pressure. Will water move in the system? No, but the pressure in the pipe will remain.
It is the same with electricity, only in order to fully explain the phenomenon, it is necessary to consider such a concept as current strength.
What is amperage?
There is always voltage in the outlet, but is there a constant current? No, and here's why.
Electric current is the directed movement of electrons, which, with a constant current, occurs in one direction, and with an alternating current, in different directions, but with a certain frequency. An electric current can appear in a circuit only under the action of a load, that is, when a consumer appears. Otherwise, there will be only voltage on the line.
Any electric current has its own strength, and when it flows through the human body, it causes quite serious harm to the body.
What should be learned once and for all
A few simple truths related to electrical engineering should be learned once and for all, namely:
- It is not the voltage that kills, but the current strength. This simple principle was used by Nikola Tesla in his developments and experiments.
- Without voltage, there will be no current in the circuit. These two physical quantities are interrelated.
- An electric current can flow through the human body only upon contact with the current-carrying part of the circuit and the ground. Then the person actually plays the role of that very load.
- You can work under voltage without harm to the body, but a high-quality dielectric should be used that insulates from any contact with the ground.
- Even 50 mA is considered life-threatening, and can stop a person's heart on contact.
The above simple rules should be remembered and constantly remind yourself of them, especially when working with electrical circuits. And best of all, before starting such work, de-energize the line and post appropriate protective posters. After that, be sure to check if the voltage is really removed.
Watch my video to dive into this topic in even more detail: