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 The coil is placed in the magnetic field to be measured and quickly withdrawn to a region of space with a negligible magnetic field.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 work needed also depends on how the magnetic field is created. For linear non-dispersive materials, though, the general equation leads directly to the simpler energy density equation given above. A changing magnetic field, such as a magnet moving through a conducting coil, generates an electric field (and therefore tends to drive a current in such a coil). This is known as "Faraday's law" and forms the basis of many electrical generators and electric motors. Mathematically, Faraday's law is: where formula_27 is the electromotive force (or "EMF", the voltage generated around a closed loop) and is the "magnetic flux"—the product of