Magnetics of transformers and induction in metals

In summary, if the primary and secondary coils of a transformer are placed next to each other, current will induce a voltage in the secondary coil, causing current flow. This also applies to motors. However, if a sheet of steel is placed between the coils, there will still be a voltage induced, but the amount will depend on various factors such as geometry, type of steel, and frequency. It is the changing magnetic field, not the current, that induces the voltage in the secondary coil. The current in the primary coil also plays a role in inducing the voltage. Do you have a specific problem in mind?
  • #1
Sam Yerardi
2
0
If you have the primary and secondary coils of a transformer next to each other, then current will induce a voltage in the secondary coil, creating current flow. This question applies to motors as well. If I place a sheet of steel between the two coils, will I still induce a voltage? For example, say I have a steel pipe and inside the pipe I place a secondary coil of wire. Outside the pipe I place a primary coil. Can I induce a voltage in the secondary coil through the steel pipe?
 
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  • #2
The answer is yes, with a lot of qualification. How much induced voltage you get will greatly depend on specific geometry of the steel, the type of steel, the coil geometries, frequency, etc.

And, it's the changing B field that induces the voltage in the secondary, not the current.
 
  • #3
Thanks. I guess I worded the question incorrectly. I meant the current in the primary coil. Thanks again!
 
  • #4
Do you have a specific problem in mind?
 

1. How do transformers work?

Transformers work by utilizing the principle of electromagnetic induction. When an alternating current flows through the primary coil of a transformer, it creates a changing magnetic field. This changing magnetic field then induces an alternating current in the secondary coil, allowing for the transfer of electrical energy from one circuit to another at different voltage levels.

2. What is the role of magnetic materials in transformers?

Magnetic materials, such as iron, are used in transformers because they have the ability to easily magnetize and demagnetize. This allows for the efficient transfer of energy between the primary and secondary coils as the magnetic field created by the primary coil induces a current in the secondary coil.

3. How does the number of turns in a coil affect the strength of a magnetic field?

The number of turns in a coil, also known as the coil's "turns ratio", directly affects the strength of the magnetic field in a transformer. A higher turns ratio means a stronger magnetic field, which results in a higher voltage in the secondary coil.

4. Can a transformer work with direct current (DC) instead of alternating current (AC)?

No, a transformer can only work with AC due to the principle of electromagnetic induction. In order for a changing magnetic field to induce a current in the secondary coil, the current in the primary coil must also be changing. DC current does not have the necessary changing magnetic field to induce a current in the secondary coil.

5. What is the difference between a step-up transformer and a step-down transformer?

A step-up transformer has a higher turns ratio, meaning that the secondary coil has more turns than the primary coil. This results in a higher voltage in the secondary coil compared to the primary coil. A step-down transformer has a lower turns ratio, resulting in a lower voltage in the secondary coil compared to the primary coil.

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