What causes the magnetic field inside a coaxial cable?

In summary, the task involves calculating the magnetic field inside a small cylinder with a current running through the inner cylinder. The answer is zero, which may be confusing. The picture provided shows that the inner cylinder is a cylindrical shell, so there will be no inside magnetic field. However, if it were a solid conductor, the magnetic field would increase linearly with distance. The current "flows" along the cylindrical shell and there is no current enclosed inside the shell.
  • #1
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Hi. In this task we're asked to calculate the magnetic field inside the small cylinder (0>r>r1). The answer is zero, which I don't quite understand...Here is the picture:
http://bildr.no/image/WTJ1VG5F.jpeg

As the picture shows there's a current I going through the inner cylinder. Wouldn't this current generate a magnetic field at a distance 0 >r>r1?
 
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  • #2
From the shading it looks like the inner conductor is a cylindrical shell rather than a solid, in which case there will be no inside magnetic field.

If it's a solid conductor the magnetic field will increase linearly with r.
 
  • #3
Ok, thanks. So the current "flows" along the cylindrical shell? I.e inside the shell we don't enclose any current.
 

Related to What causes the magnetic field inside a coaxial cable?

1. What is a magnetic field?

A magnetic field is a region in space where a magnetic force can be felt. It is created by the movement of electric charges, such as electrons, and is represented by magnetic field lines that indicate the direction and strength of the field.

2. How is a magnetic field related to a coaxial cable?

A coaxial cable is designed with two conductors, an inner wire and an outer cylindrical conductor, which are separated by an insulating material. When an electric current flows through the inner wire, it creates a magnetic field around the cable.

3. What is the role of a magnetic field in a coaxial cable?

The magnetic field in a coaxial cable helps to keep the electric current flowing in a single direction. This is known as the "skin effect", where the outer conductor contains the magnetic field and prevents it from interfering with the inner conductor. This allows for a more efficient transmission of signals through the cable.

4. How does the magnetic field affect the signal transmission in a coaxial cable?

If the magnetic field is disrupted or weakened, it can cause interference and distortions in the signal being transmitted through the cable. This can result in a decrease in the quality of the signal or even a complete loss of transmission.

5. Can a magnetic field be shielded in a coaxial cable?

Yes, a coaxial cable is designed with a shield layer, often made of metal, to protect the inner conductor and signal from external magnetic fields. This allows for a more reliable and consistent signal transmission through the cable.

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