How can I create a very strong magnetic field?

Question

anonymous · Answer

For example, If i were to create a device that I could hold it 1ft from the ground I could lift a .5lb metal of the ground and make it stick to my hand.

anonymous · Answer

Stick to the magnet I mean not my hand.

anonymous · Answer

Maybe is magnetic force what I tried to say.

turingtest · Answer

Coil a conducting wire very tightly around a cylindrical object as many times as possible and run a current through it. That is how electromagnets work. Do it with a strong enough current and enough coils and you can lift a car for example.

turingtest · Answer

...insulate the wire btw

turingtest · Answer

Ampere's Law is the formula you want to calculate the strength of the magnetic field you would make:
$$B =μ_0 nI$$$$\text{where }I\text{  represents current}$$$$ n=\frac N\ell\text{ represents the number of turns per unit length}$$$$\text{and }\mu_0=4\pi\times10^{-7}\text{ is the magnetic constant}$$

anonymous · Answer

Just buy a Strong Neodymium Magnets from Radio Shack or the Internet.  You didn't specify an electromagnetic force, so why not just use a permanent magnet?