This means that these three values cannot be independent; If you know two of them, you can lead the third. How do physicists deal with this? We define featherlight speed as exactly 299 792 458 meters per second. (How do we know that it is true? Because we define the meter when the featherlight of the distance moves in 1/299 792.458 seconds.)M0) and apply this value with the speed of featherlight to calculate the electric constant (me0).
It may seem to be a scam, but to even start doing actual learning, at some point we must create arbitrary units and define some parameters. In fact, when you come to him, all measurement systems are invented, just like all words are invented.
Free space permeability
Magnetic fields (represented by the symbol B) You can create magnets, as shown in the photo up. But because of this interdependence we talked about, they can also be done by moving electrical charges. (I apply a tiny term “loads” for charged particles, such as electrons.) It is described by Biot-Savart law:
You can see a magnetic constant (M0) there. We also have the value of the electric charge (Q) moving at a certain speed (v). This says that the magnetic field increases with an electric charge and decreases with a distance (R) From a moving load – and a magnetic constant tells us exactly how much it changes.
Of course, we do not often deal with movable electrons. But all the time we deal with streams of moving electrons: it is an electric current that we can measure. If we know the charge of particles in the backstage, the number of Coulbs flowing per second gives us electricity (AND) in ampera. And we can write the above equation in current terms: B = m0I/(2πr).
It is everywhere
It tells us Electricity produces a magnetic field. This is used in all types of machines. For example, it gives us electromagnets, in which magnetic force can be turned on and off to carry metal objects in factories and scrap metal. In this way, audio speakers create a sound: an electric signal is vibrated by a magnetic controller that generates pressure waves in the air.
Also Magnetic fields affect electric currents. This is how the engines work. The wire coil runs electricity in the presence of a magnetic field, which usually arises with some enduring magnets. The strength on the wire coil makes it turn around and is your engine. It can be a fan engine, part of the AC compressor or the main drive for an electric car.
Wait! There are more. Just as the changing electric field creates a magnetic field, The changing magnetic field creates an electric field– And it produces electricity. In this way, most of our power is generated. Some energy source – internship, wind, moving water, whatever – connects a turbine that rotates the coil in the magnetic field. The changing magnetic stream induces the tension in the coil, transforming mechanical energy into electricity, which can be transferred to the house.
Measuring magnetic enduring
How can we measure M0? One method uses the so -called current balance. A uncomplicated version of this has two parallel cables that transfer electricity (AND) In opposite directions, as shown in the diagram below. Then you will hang two cables with strings so that they can separate, in this way:
The electricity in each wire creates a magnetic field in the place of the second wire, which spreads them. When they leave, the magnetic force decreases, and the levels of the voltage component during the support increases (due to the change of the angle). When these two forces are equal, the cables will be “balanced”.
If you know the value of electricity and the distance between the wires (R), you can determine the magnetic constant, M0. Then, as we showed above, you can apply this value along with a certain speed of featherlight to calculate the electric constant, me0.
So yes, you can say that magnetic constant is very critical. Oh, what is this constant value? According to the International Committee for Weights and Army, M0 = 1,256637061272 × 10-6 Not applicable2. No more, no less.