Lenzs law is a fundamental law in electromagnetism that specifies the direction of the electric current induced in a conductor by a changing magnetic field. It states that the magnetic field created by the induced current opposes changes in the initial magnetic field. Lenzs law is named after physicist Emil Lenz, who formulated it in 1834.
Lenzs law is a qualitative law that specifies the direction of induced current, but states nothing about its magnitude. It predicts the direction of many effects in electromagnetism, such as the direction of voltage induced in an inductor or wire loop by a changing current, or the drag force of eddy currents exerted on moving objects in a magnetic field. Lenzs law may be seen as analogous to Newtons third law in classical mechanics and Le Chateliers principle in chemistry.
Lenzs law is contained in the rigorous treatment of Faradays law of induction, where it finds expression by the negative sign: which indicates that the induced electromotive force and the rate of change in magnetic flux have opposite signs. The law allows us to predict the direction of an electromotive force (EMF) induced by a changing magnetic field through a loop or coil of wire. The direction of the induced current is always such as to oppose the change in the circuit or the magnetic field that produces it.
In summary, Lenzs law is a fundamental law in electromagnetism that specifies the direction of the electric current induced in a conductor by a changing magnetic field. It predicts the direction of many effects in electromagnetism and is contained in the rigorous treatment of Faradays law of induction. The law allows us to predict the direction of an electromotive force (EMF) induced by a changing magnetic field through a loop or coil of wire.
