# EM fields and magnetic induction from an experiment

• Quarinteen
We took a 5 inch bolt with a .25 radius. We coiled copper wire around the threads. When I hit the end I wrapped it in electrical tape to separate it to go over it again. Then wrapped it in electrical tape again. We added enough tape for the end to fit in a speaker magnet that has a 2.25 inch radius with a hole in the center orb a 3/4 inch diameter.Then we stuck the bolt in and connected the end of the copper to a galvanometer then took a couple of speaker magnets and ran them from the base up to show the kids how it will generate a little electricity. The question came up if we could store it. I am sure there is but I have

#### Quarinteen

If you take copper wire and wrap it tightly around a bolt will that alone create and hold a magnetic field?

I add an image for clarification

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As long as you have current running through the coil, yes. To get a permanent magnet the bolt would have to be made of a specific material. I'm not sure regular steel is easily magnetized permanently.

Quarinteen said:
Summary:: Hello I was working on a project and got side tracked with EM fields. I opened this thread in hopes to add to it and keep it sort of like a running log. I want to start at ground 0 like a kid and expand on that base. With that let me just start with my first question.
No, the PF does not work like that. It is not for logs/blogs -- it is for answering specific questions, generally one question per thread. Please confine this thread here to your specific question about currents in wire loops and magnetizing bolts. Thank you.

Quarinteen said:
If you take copper wire and wrap it tightly around a bolt will that alone create and hold a magnetic field?
No. It would take either a current in the wire as @Drakkith says, or a permanent magnet nearby. The Google search term would be Magnetic Induction.

https://en.wikipedia.org/wiki/Magnetic_field#The_B-field

berkeman said:
No, the PF does not work like that. It is not for logs/blogs -- it is for answering specific questions, generally one question per thread. Please confine this thread here to your specific question about currents in wire loops and magnetizing bolts. Thank you.
Sorry let me clarify. I did not mean like a blog. It will be a running question about this topic. I will just add future questions about the same topic to this instead of opening a bunch of threads. If that is acceptable.

Quarinteen said:
Sorry let me clarify. I did not mean like a blog. It will be a running question about this topic. I will just add future questions about the same topic to this instead of opening a bunch of threads. If that is acceptable.
We can give it a try to see what happens. Please read through the link that I posted above and let us know if you have specific questions. Thank you.

Drakkith said:
As long as you have current running through the coil, yes. To get a permanent magnet the bolt would have to be made of a specific material. I'm not sure regular steel is easily magnetized permanently.
That’s what I thought, but it seems I have an exception.

we took a 5 inch bolt with a .25 radius. We coiled copper wire around the threads. When I hit the end I wrapped it in electrical tape to separate it to go over it again. Then wrapped it in electrical tape again. I added enough tape for the end to fit in a speaker magnet that has a 2.25 inch radius with a hole in the center orb a 3/4 inch diameter.

I stuck the bolt in and connected the end of the copper to a galvanometer then took a couple of speaker magnets and ran them from the base up to show the kids how it will generate a little electricity. The question came up if we could store it. I am sure there is but I have no clue. So we started messing around and took a small capacitor and soldiered it to a couple of wires then attached it to the ends of the copper on the screw. We tried to measure it and nothing came back but there was a reaction to it from what were using to measure magnetic fields.

I didn’t think it was right so I made another screw wrapped in wire and left the capacitor off. We checked it’s field and there was none as expected. So now I’m wondering why the other one held its field. Surley the capacitor did nothing.

for clarification

## 1. What is an EM field?

An EM (electromagnetic) field is a physical field that is created by electrically charged particles and is responsible for the interaction between electrically charged particles. It is composed of both electric and magnetic components and can exist in a vacuum.

## 2. How is an EM field measured in an experiment?

In an experiment, an EM field can be measured using instruments such as an electromagnetic field meter or a Gaussmeter. These instruments can detect and measure the strength and direction of the EM field at a specific location.

## 3. What is magnetic induction?

Magnetic induction is the process by which a changing magnetic field can induce an electric current in a conductor. This phenomenon was first discovered by Michael Faraday and is the basis for many modern technologies such as generators and transformers.

## 4. How is magnetic induction demonstrated in an experiment?

Magnetic induction can be demonstrated in an experiment by using a coil of wire and a magnet. When the magnet is moved inside the coil, a current is induced in the wire. This can be observed by connecting the ends of the wire to a light bulb, which will light up when the magnet is moved.

## 5. What are some real-world applications of EM fields and magnetic induction?

EM fields and magnetic induction have a wide range of applications in modern technology. Some examples include electric generators, transformers, motors, MRI machines, and wireless charging devices. They are also used in everyday objects such as speakers, doorbells, and credit cards.