Magnetic fields key terms

Magnetic Flux Density

The measure of the strength of a magnetic field per unit area, defined as the force per unit current per unit length on a current-carrying conductor.

Force on a Current-Carrying Conductor

The force experienced by a conductor carrying an electric current in a magnetic field, calculated using the formula F = BIL, where F is the force, B is the magnetic flux density, I is the current, and L is the length of the conductor in the field.

Magnetic Flux Density

The measure of the strength of a magnetic field per unit area, defined as the force per unit current per unit length on a current-carrying conductor.

Force on a Conductor

The force experienced by a current-carrying conductor in a magnetic field, calculated using the formula F = BIL, where F is the force, B is the magnetic flux density, I is the current, and L is the length of the conductor.

Right-Hand Rule

A method used to determine the direction of the magnetic force on a current-carrying conductor in a magnetic field.

Force Direction

The direction in which a force acts on a charged particle or current-carrying conductor when placed in a magnetic field, determined using hand rules.

Magnetic flux density

The measure of the strength of a magnetic field per unit area, defined as the force per unit current per unit length acting on a current-carrying conductor in the field.

Force on a conductor

The force experienced by a current-carrying conductor in a magnetic field, calculated using the formula F = BIL, where F is the force, B is the magnetic flux density, I is the current, and L is the length of the conductor in the field.

Magnetic Force

The force experienced by a moving charged particle in a magnetic field, calculated using the formula F = qvB sin(θ), where F is the magnetic force, q is the charge, v is the velocity, B is the magnetic flux density, and θ is the angle between the velocity and magnetic field direction.

Lorentz Force

The combined effect of electric and magnetic forces on a charged particle, expressed as F = q(E + v × B), where F is the total force, q is the charge, E is the electric field, v is the velocity of the particle, and B is the magnetic field.

Magnetic flux density

The measure of the strength of a magnetic field per unit area, defined as the force per unit current per unit length acting on a current-carrying conductor.

Centripetal force

The net force required to keep an object moving in a circular path, directed towards the center of the circle, which for charged particles in a magnetic field is provided by the magnetic force.

Magnetic Force

The force experienced by a charged particle moving through a magnetic field, calculated using the formula F = qvB sin(θ), where F is the magnetic force, q is the charge, v is the velocity, B is the magnetic flux density, and θ is the angle between the velocity and magnetic field.

Centripetal Force

The net force required to keep an object moving in a circular path, directed towards the center of the circle, calculated using the formula F_c = mv^2/r, where F_c is the centripetal force, m is the mass, v is the velocity, and r is the radius of the circular path.

Path direction of charged particles

The direction in which a charged particle moves in a magnetic field, determined by the right-hand rule.

Magnetic force on charged particles

The force experienced by a charged particle moving through a magnetic field, calculated using the formula F = qvB sin(θ), where F is the magnetic force, q is the charge, v is the velocity, B is the magnetic flux density, and θ is the angle between the velocity and magnetic field.

Magnetic Flux

Magnetic flux is defined as the product of the magnetic field strength and the area perpendicular to the field through which the lines of magnetic force pass.

Flux Linkage

Flux linkage is defined as the product of the number of turns in a coil and the magnetic flux through one turn of the coil.

flux linkage

The product of the number of turns in a coil and the magnetic flux through one turn, measured in Weber turns (Wb turns).

magnetic flux

The measure of the quantity of magnetism, taking into account the strength and extent of a magnetic field, measured in Webers (Wb).

Magnetic flux linkage

The product of the magnetic flux through a coil and the number of turns in the coil, influencing induced emf.

Induced emf

The electromotive force generated in a circuit due to a change in magnetic flux, as described by Faraday's law.

magnetic flux

The product of the magnetic field strength and the area perpendicular to the field through which the field lines pass, measured in Weber (Wb).

flux linkage

The product of the magnetic flux and the number of turns in a coil, representing the total magnetic field passing through the coil, measured in Weber-turns (Wb-turns).

Faraday's law

The induced emf in a circuit is directly proportional to the rate of change of magnetic flux through the circuit.

induced emf

induced emf: a curriculum-specific A-Level Physics term used in Electromagnetic induction. It supports the learning objective to use Faraday's law to calculate induced emf. by naming the field quantity, relationship or interpretation students must apply, rather than giving a generic definition. In exam answers, use it with the correct unit, direction, sign convention or graph interpretation where relevant.

Lenz's Law

The principle stating that the direction of induced current is such that it opposes the change in magnetic flux that produced it.

Induced Effects

The changes in current or voltage that occur in a circuit due to a changing magnetic field, as described by Lenz's Law.

Faraday's Law

The induced electromotive force (emf) in a closed circuit is directly proportional to the rate of change of magnetic flux through the circuit.

Lenz's Law

The direction of the induced current is such that it opposes the change in magnetic flux that produced it.