| scalar quantity equal to the line integral of a vector quantity along a path C from point a to point b in which charge carriers can be displaced|
where A and B are respectively a magnetic vector potential and the magnetic flux density at a point of the path C, v is the velocity with which that point is moving, r is position vector of the point, and t is time
Note 1 to entry: If the points a and b are at rest, i.e. their velocities are zero (va = vb = 0), the induced voltage is equal to the time derivative of the protoflux corresponding to the path C, with a positive or negative sign according to the convention in IEC 60375.
Note 2 to entry: The first term in the integrand results from Faraday’s law (see Maxwell equations) and the second one from the non-relativistic Lorentz transformation of the electromagnetic field tensor.