About Bar Magnets - Magnetic Force And How To Choose

Bar magnets can be classified into one of two types: permanent and temporary. Permanent magnets are always in the “on” position; that is, their magnetic field is always active and present. A temporary magnet is a material that becomes magnetized when acted upon by an existing magnetic field. Perhaps you used a magnet to play with your mother’s hairpins as a child. Remember how you were able to use a hairpin attached to a magnet to magnetically pick up a second hairpin? That’s because the first hairpin became a temporary magnet, thanks to the force of the magnetic field surrounding it. Electromagnets are a type of temporary magnet which becomes “active” only when an electric current passes through them creating a magnetic field.