A magnetic field is invisible, but it can be detected using a magnetic compass. A compass contains a small bar magnet on a pivot so that it can rotate. The compass needle points in the direction ...

A permanent magnet is always magnetic. It has an invisible magnetic field. Only certain materials, such as iron, feel a magnetic force. Permanent magnets can come in lots of different shapes and ...

When an electric current passes through a metal wire, a magnetic field forms around that wire (see diagram at right). Likewise, a wire passing through a magnetic field creates an electric current ...