Description
ED Tech Press Electromotive Forces (Hb 2021) by Hopkins
The word force in this case is not used to mean mechanical force, measured in newtons, but a potential, or energy per unit of charge, measured in volts. In electromagnetic induction, Electro-Motive force (emf) can be defined around a closed loop as the electromagnetic work that would be done on a charge, if it travels once around that loop. For a time-varying magnetic flux linking a loop, the electric potential scalar field is not defined due to circulating electric vector field, but nevertheless an emf does work, that can be measured as a virtual electric potential around that loop.