Force between 2 electromagnets

[Shahryar]

I am looking forward to know how to calculate the force between 2 electromagnets. what is the formula to find attraction and repulsion forces between them ?

Thank you.

 

[mfb]

In general, those forces are complicated. If the electromagnets are far away from each other (relative to their size), you can approximate them as dipoles. Otherwise, the Biot-Savart law can be used.
See Wikipedia for basic formulas.

 

[Shahryar]

In general, those forces are complicated. If the electromagnets are far away from each other (relative to their size), you can approximate them as dipoles. Otherwise, the Biot-Savart law can be used.
See Wikipedia for basic formulas.

I have 2 iron cores with 10mm dia x 20mm length. with a coil with 500 turns of 0.3mm wire thickness, i guess i can pass 0.2 Ampere through that wire. The maximum distance between these 2 electromagnets is 15mm and minimum is 2mm