Electromotive force
In circuit science, the electromotive force (English: electromotive force, abbreviated as emf) characterizes the characteristics of some electrical components that supply electrical energy. These circuit elements are called "electromotive force sources". Electrochemical cells, solar cells, fuel cells, thermoelectric devices, generators, etc., are electric potential. The energy supplied by the electromotive force source is the electromotive force per unit charge. Assuming that the charge moves through an electromotive force source, the energy is obtained, then the electromotive force of the element is defined as. In general, this energy is the work of separating the positive and negative charges. Since this positive and negative charge is separated into both ends of the element, the corresponding electric field and voltage difference occur. In electromagnetism, the electromotive force is divided into two types: "induced electromotive force" and "dynamic electromotive force". According to Faraday's law of induction, in the time-dependent magnetic field of the closed circuit, as the magnetic field changes over time, there will be induced electromotive force in the closed circuit. The induced electromotive force is equal to the path of the electric field along the closed circuit. Charged particles in the closed circuit will feel the electric field, resulting in current. ...