Electro Magnetism – From the wire to the magnet


Hello internet and welcome to everWonder. Today’s topic is the second type of magnetism. If you don’t have any magnets at hand, you
can always create one by running an electric current through a wire. Even if it isn’t ferromagnetic. Running electricity will always create a magnetic
field. And if you’re now wondering what the first
type of magnets is? Well, I already did a video about them. So, if you haven’t seen it, just click on
the link in the Infocards. I’ll be here by the time you come back. In this video, there are several things to
discuss. What does the magnetic field of a wire look
like? Why do connected parallel wires repel or attract
each other? And why does a coil produce an electromagnet? Surprisingly, if you can hold a wire in your
right hand, you’ve got everything you need to answer those questions. First, let’s make it very simple. If you imagine holding the wire in your right
hand and point your thumb in the direction of the electric current, then your fingers
show you the direction of the flux lines. If the current is flowing towards you, indicated
by a dot, the flux lines travel counterclockwise. The other way around, indicated by a cross,
they of course travel clockwise. It all just depends on your frame of reference. Now we know how the flux lines of a wire behave. Next: Why do connected parallel wires repel
or attract each other? First, a “connected parallel wire” is
nothing but a wire that was bent to be parallel. Now let’s look at the direction of the electrical
current. Applying the same rule with our right hand,
we can draw in the flux lines. As seen from the top, it would look like this. The dot and cross again represent the directions
of the electric current. The flux lines would collide as they travel
towards each other. But since this isn’t possible – flux lines
can’t cross –, they will all just get bunched together between the wires. This builds up pressure in the middle, which
in turn pushes the wire apart. So, in this constellation, the wires repel
each other. If we change the connections a bit, so the
electric current of both wires is flowing in the same direction, the layout of the flux
lines changes. This time, both are counterclockwise, or they
simply flow in the same direction. Instead of getting clumped together in the
middle, they will combine if necessary and act as a single flow. This, on the other hand, creates pressure
on the outside, pushing both wires together. Or to put it simply, the wires attract each
other. An easy way to think about it is imagining
the flux lines as stretched out rubber bands. If you bunch up lots of them between two wires,
the wires will eventually be pushed apart. Otherwise, on the outside, they will contract
and pull the wires together. This analogy also works for the last video
on how magnets attract in the first place. Again, just think of the lines as stretched
out rubber bands. The flux lines will behave in exactly the
same way, causing the attraction or repulsion of objects. But back to our topic of electromagnets. We still have one unanswered question. Why does a coil produce an electromagnet? Let’s look again at our parallel wire, with
the flux lines and everything. Additionally, I’ll put both views next to
each other. Just to make it clearer. This is the basis for the next step. Isn’t a coil nothing but a wire that was
bent over and over again? This changes the complete layout of the flux
lines. Not only is the electric current flowing in
the opposite direction but also in the same direction because of the loops. This lets the flux lines combine in this area,
while they get bunched up in the center of the coil. This magnetic field looks exactly like that
produced by bar magnets. And there you have it. Just by using your right hand, you can explain
why a coil produces a magnetic field. Let me just make a small addition. You can increase the strength of the electromagnet
by placing a ferromagnetic metal inside the coil. This gathers the flux lines and makes it easier
for them to travel through. As a result, the electromagnet becomes a lot
more powerful. And with that being said. See you in the next video. Have a good one!

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2 thoughts on “Electro Magnetism – From the wire to the magnet”

  1. Gagandeep Baath says:

    Wow, I didn't expect to understand much but you surprised me. Really good explanation. Thanks!

  2. Mamta Battina says:

    Easy explanation.

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