Can I Use an Electromagnet to Repel Aluminum?

Click For Summary

Homework Help Overview

The discussion revolves around the use of an electromagnet to repel an aluminum bar. The original poster describes their setup using a microwave oven transformer and a D cell battery, expressing confusion about the behavior of the electromagnet with non-ferrous metals like aluminum.

Discussion Character

  • Conceptual clarification, Assumption checking, Exploratory

Approaches and Questions Raised

  • Participants explore the nature of aluminum as a paramagnetic material and question the expected behavior of non-ferrous metals in magnetic fields, particularly regarding the role of eddy currents.

Discussion Status

There is an ongoing exploration of the principles behind electromagnetism and the specific characteristics of aluminum. Some participants have offered insights into the limitations of using a DC magnetic field for generating eddy currents, while others are considering adjustments to the original setup to potentially achieve the desired effect.

Contextual Notes

Participants note that the original poster's attempts to modify the electromagnet's configuration have not yielded the expected results, and there is a suggestion to consider using an AC power source to create eddy currents.

Yummy Yum
Messages
3
Reaction score
0

Homework Statement


I have made an electromagnet using the primary core of a microwave oven transformer and a 1.5 D cell battery.

I would like to use the electromagnet to repel an aluminum bar (1 in. dia., 3 in. in length, and 1/4 in. thick; it is shown in the picture)

For some reason, the electromagnet only attracts to ferrous metals, but does not repel non ferrous metals (like the aluminum bar). According to my research, some non ferrous metals will not be repelled by electromagnets, but aluminum should definitely be repelled.

I've attached a picture of my electromagnet

Homework Equations

The Attempt at a Solution


I've done everything I can think of to try and make the electromagnet repel the aluminum bar. I've tried switching the wires from positive to negative and vise versa, changing the battery size, and changing the thrust direction.

What can I do to make my electromagnet repel this aluminum bar?

Thanks
 

Attachments

  • diagram.png
    diagram.png
    125.7 KB · Views: 1,113
Physics news on Phys.org
Yummy Yum said:

Homework Statement


I have made an electromagnet using the primary core of a microwave oven transformer and a 1.5 D cell battery.

I would like to use the electromagnet to repel an aluminum bar (1 in. dia., 3 in. in length, and 1/4 in. thick; it is shown in the picture)

For some reason, the electromagnet only attracts to ferrous metals, but does not repel non ferrous metals (like the aluminum bar). According to my research, some non ferrous metals will not be repelled by electromagnets, but aluminum should definitely be repelled.

I've attached a picture of my electromagnet

Homework Equations

The Attempt at a Solution


I've done everything I can think of to try and make the electromagnet repel the aluminum bar. I've tried switching the wires from positive to negative and vise versa, changing the battery size, and changing the thrust direction.

What can I do to make my electromagnet repel this aluminum bar?

Thanks
Aluminum is paramagnetic, so it has a slight attraction to magnetic fields.
 
SammyS said:
Aluminum is paramagnetic, so it has a slight attraction to magnetic fields.
But, shouldn't non ferrous metals like aluminum and copper be repelled due to Eddy currents?
 
Yummy Yum said:
But, shouldn't non ferrous metals like aluminum and copper be repelled due to Eddy currents?
You don 't get eddy currents with a dc magnetic field.
As for when you thrust, that force is probably too weak and of too short duration to move the metal.
 
rude man said:
You don 't get eddy currents with a dc magnetic field.
As for when you thrust, that force is probably too weak and of too short duration to move the metal.
Sorry, I'm kind of new to this. So, if I wanted to create eddy currents, how would I adjust my model to use an ac power source?
 
For safety's sake I suggest a step-down transformer 115V to maybe 26V (a common type), then you need a resistor in series with your coil to keep the current manageable. Idea is not to overload the transformer.
 

Similar threads

Replies
7
Views
3K
  • · Replies 37 ·
2
Replies
37
Views
5K
  • · Replies 9 ·
Replies
9
Views
9K
  • · Replies 4 ·
Replies
4
Views
6K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 2 ·
Replies
2
Views
8K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
5K
Replies
5
Views
4K