What is a magnetic constant and why is it important?

This means that these three values ​​cannot be independent; If you know two of them, you can get the third. How do physicists deal with this? We define the fast light exactly 299,792,458 meters per second. (How do we know it’s correct? Because we define a meter while the light of the distance travels in 1 / 299,792,458 seconds.) Then we measure magnetically constantly (m₀) and use that value together with the speed of light to calculate the electrical constant (e₀).

It may seem to be cheating, but even to start performing real science, at some point we have to compile only arbitrary units and define some parameters. In fact, when you get on it, all measurement systems are composed, just as all the words are assembled.

Free space permeability

Magnetic fields (represented by symbol) B) Magnets can be created, as shown at the top above. But because of that interdependence we discussed, they can also be made by moving electric costs. (I use a brief term “accusation” for collected particles, such as electrons.) This is described by law Biot-Savart:

You can see a magnetic constant (m₀) There. We also have the value of electric charge (k) movement with a specified speed (in). So this says that the magnetic field increases with electric charge and decreases remote (r) From the moving charge – and the magnetic constant tells us exactly how much varies.

Of course, we do not deal with individual moving electrons very often. But we are dealing with streams of continuous electrons: it is an electric current, which we can measure. If we know the charges of the particles in Coulbs, then our number of tower running for a second gives us electricity (Me) in the amps. And we can write the equation above in terms of current: B = m₀I / (2πr).

It’s all over

What this tells us is that Electric current generates a magnetic field. This is used in all types of machines. For example, it gives us electromagnets, where the magnetic force can turn on and off to move metal objects in factories and peas. It is also how sound sound beep sounds: the electrical signal vibrates a magnetic driver, which generates waves under pressure in the air.

Too Magnetic fields affect electric currents. This way the engines work. There is a momentary run through the wire coil in the presence of a magnetic field that is usually created with some permanent magnets. The force on the wire coil causes it to turn around, and there is your engine. It could be a fan motor, part of your alternating current or main drive for an electric car.

Wait! There are still. As the variable electric field creates a magnetic field, Changing the magnetic field creates an electric field– This produces electricity. This is how most of our powers are generated. Some source of energy-steam, wind, moving water, whatever the turbine rotates the coil in the magnetic field. The variable magnetic stream encourages voltage in coil, converting mechanical energy into electricity that can be transferred to your home.

Measurement of magnetic constant

How can we measure m₀? One method uses what is called the current balance. The simple version of this has two parallel wires that carry electric current (Me) In opposite directions, as shown in the diagram below. Then you suspend two wires with strings so that they can be separated, like this:

The current in each wire creates a magnetic field at the location of another wire and it separates them. While being moved, the magnetic force reduces the horizontal component of tension in support carrier increases (due to the change of the angle). Once these two strengths are equal, the wires will be “balanced”.

If you know the power value and the distance between the wire (r), you can determine the magnetic constant, m₀. Then, as we have shown above, you can use this value together with a defined speed of light to calculate the electrical constant, e₀.

Well yes, everything in all, you could say that the magnetic constant is quite important. Oh, and what is the constant value? According to the International Board of Weights and Measures, m₀ = 1.256637061272 × 10^-6 N / a². No more, not less.