Units

Units in Magnetism and Electromagnetism

Force on a current-carrying conductor in a magnetic field

• The unit for force is the newton (N).
• Current is measured in amperes (A).
• Length is measured in metres (m).
• Magnetic field strength is given in tesla (T).

Magnetic field due to a current-carrying wire

• Magnetic field strength, also known as magnetic flux density, is measured in tesla (T).
• Current is measured in amperes (A).
• Distance from the wire is measured in metres (m).

Induced potential difference (and current) in a wire moving in a magnetic field

• The induced potential difference is measured in volts (V).
• The induced current is measured in amperes (A).
• The speed of the wire is given in metres per second (m/s).
• Length of the part of the wire in the field is in metres (m).
• Magnetic field strength is measured in tesla (T).

Magnetomotive force, magnetic field strength and magnetic flux

• Magnetomotive force is measured in ampere turns (At).
• Length is measured in metres (m) for the calculation of magnetic field strength.
• Magnetic field strength is given in ampere per metre (A/m).
• Magnetic flux is measured in webers (Wb).

Flux linkage and Faraday’s law

• The unit for flux linkage is weber turns (Wbt).
• The change in flux linkage is measured in weber turns per second (Wbt/s).
• The induced potential difference (or emf) is given in volts (V).

Units related to magnetism and electromagnetism

• Magnetic field strength, also known as magnetic flux density, is measured in tesla (T).
• The unit for magnetic field, also known as magnetic induction, is tesla (T).
• Magnetomotive force is measured in ampere turns (At).
• Magnetic flux is given in webers (Wb).
• The unit for flux linkage is weber turns (Wbt).