How do I calculate the repelling Force of an Electromagnet?

In summary, the conversation discusses finding the formula for calculating the amount of current needed to create an electromagnet with enough strength to repel a force of 2000 Newtons. It is mentioned that the formula is dependent on the shape and dimensions of the magnet and the other magnet it will repel. The formula involves solving for the pole strength of each electromagnet and the current needed. Additionally, there is a discussion on the energy density and force in the airgap between two magnets.
  • #1
jason Kenedy
2
0
Hello everyone, I am working on a project and I am trying to figure out the formula to use. My goal is to calculate the amount of current needed to create an electromagnet with a strong enough field strength to repel a force of 2000 Newtons.
thank you
 
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  • #2
jason Kenedy said:
My goal is to calculate the amount of current needed to create an electromagnet with a strong enough field strength to repel a force of 2000 Newtons.
The short answer is: 400000 A/m.
But of course it depends on:

* What kind of magnet ( shape ).
* Dimensions of the magnet and the other magnet to be repelled. ( for example unmagnetized iron will always be attracted ).

So you need to fill out "All known data:".
 
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  • #3
Thanks. Actually I just found this formula. I can reverse solve for m1 and m2 which is the pole strength of each electromagnet I would be using for the project.
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and then solve for the current I need.
 
  • #4
I don't recognize this formula. What is m1 and m2: Masses, or?

Say you have two magnets kept apart with a distance, s. The cross section areas of the magnets are A. The energy density within the airgap will be

Edens = ½*B*H [ J/m3 ] ( = ½*μ0*B2 )

The energy in the airgap will be E = ½*B*H*Volumeairgap = ½*B*H*s*A

Now, you can find the force: F = dE/ds = ½*B*H*A.

But what is the size of A?
 

FAQ: How do I calculate the repelling Force of an Electromagnet?

1. How do I calculate the repelling force of an electromagnet?

The repelling force of an electromagnet can be calculated using the formula F = (N1 x N2 x μ0 x A)/d^2, where F is the force in Newtons, N1 and N2 are the number of turns in the coils, μ0 is the permeability of free space, A is the cross-sectional area of the coils, and d is the distance between the two magnets.

2. What is the unit of measurement for the repelling force of an electromagnet?

The unit of measurement for the repelling force of an electromagnet is Newtons (N). This is the standard unit for force in the International System of Units (SI).

3. How does the number of turns in the coils affect the repelling force of an electromagnet?

The number of turns in the coils has a direct impact on the repelling force of an electromagnet. The more turns there are, the stronger the magnetic field will be, resulting in a greater repelling force.

4. Can the repelling force of an electromagnet be increased?

Yes, the repelling force of an electromagnet can be increased by increasing the number of turns in the coils, using a stronger magnetic material, or decreasing the distance between the two magnets.

5. How do I measure the distance between two magnets to calculate the repelling force?

The distance between two magnets can be measured using a ruler or caliper. It is important to measure the distance accurately in order to get an accurate calculation of the repelling force. Make sure to measure the distance from the center of one magnet to the center of the other.

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