Calculator Electromagnet: Field Strength and Flux Density

Calculates the magnetic field strength and the flux density of an electromagnet from the current, length and number of turns. An electromagnet consists of a conductive coil through which current flows. This current creates a magnetic field. The field strength H of this magnetic field is calculated from the current strength I in amperes, the number of turns n and the length of the coil L in meters as H = I * n / L. To calculate the flux density from the field strength, see field strength.
Please enter amperage, number of turns and coil length. The length of the coil refers to the distance between its beginning and end, not to the length of the wire when unwound.

Example: if 8 amperes flow through a 20 centimeter long coil with 75 turns, the field strength is 3000 amperes per meter and the flux density is almost 3.8 milliteslas.

In contrast to permanent magnets, electromagnets can be switched on and off. To do this, electromagnets require electricity as long as the magnetic force is to last.
One application for very strong electromagnets is lifting heavy loads made of iron, for example scrap metal, using a scrap yard magnet. These have field strengths of around one Tesla. The load is released again by switching off the current.
To put it simply, electric motors consist of a permanent magnet that rotates in an electromagnet, or vice versa. The current generates the rotation and thus converts electrical energy into kinetic energy.
Electromagnets and electric motors based on them come in a very wide range of sizes and strengths. In medical technology, there are electric motors that are less than a micrometer (a thousandth of a millimeter) in size. Among the largest electromagnets are those used in fusion reactors and can achieve field strengths of over 20 Tesla.