Search coil by computer to determine displacement in multiple dimensions. Additionally, a second search coil can be added to measure torsional rotation. A more crude search coil also called exploring coil is also used in laboratory experiments in schools to measure the magnetic field in a certain region of space. In this case the search coil consists of a simple wire coil or solenoid connected to a sensitive ammeter or galvanometer. The coil is placed in the magnetic field to be measured and quickly withdrawn to a region of space with a negligible magnetic field. As the search coil moves the magnetic
Magnetic field the magnetic field generated by a steady current. Also in this work, Ampère introduced the term electrodynamics to describe the relationship between electricity and magnetism. In 1831, Michael Faraday discovered electromagnetic induction when he found that a changing magnetic field generates an encircling electric field. He described this phenomenon in what is known as Faraday's law of induction. Later, Franz Ernst Neumann proved that, for a moving conductor in a magnetic field, induction is a consequence of Ampère's force law. In the process, he introduced the magnetic vector potential, which was later shown to be equivalent to the underlying mechanism