I have been doing some serious research, and yet to come to a direct answer.I am trying to figure out how much magnetic power wrapped around a core of some sort is produced per turn of wireThis may seem complicated, But I can try to simplify it.I have seen those giant magnets that lift junk vehicles in junk-yardsI am trying to make a miniature one that can hold on to over 5 pounds of weightHow many turns of wire do I need to lift a certain amount of weight.For example: 50 turns 50 grams (Just an example.)And also the voltage and amperage is almost not an issue, unless it\'s a ridiculous amount of amperage required just to lift a small amountIm talking a max of about 5-10 amps I have availableI can probably even use an old power supply from a computer to get even more amperageThank you.useing a current in a coil; generally speaking - doubling the coil windings will doubel the magnetic field for a given curent strengthUsing a core (iron, steel, nickel, cobalt, or ferrous material) in the electromagnet will concentrate the field and give a better strengthOther related question