5 can be argued independently
from Faraday’s law using the Lorentz force on moving charges However,
even if the charges are stationary [and the q (v × B) term of the Lorentz
force is not operative], an emf is nevertheless induced in the presence of a
time-varying magnetic field Thus, moving charges in static field and static
charges in a time-varying field seem to be symmetric situation for Faraday’s
law This gives a tantalising hint on the relevance of the principle of
relativity for Faraday’s law