scalar density
71Electrical resistivity and conductivity — This article is about electrical conductivity in general. For the specific conductance of aqueous solutions, see Conductivity (electrolytic). For other types of conductivity, see Conductivity. Electrical resistivity (also known as resistivity,… …
72General relativity — For a generally accessible and less technical introduction to the topic, see Introduction to general relativity. General relativity Introduction Mathematical formulation Resources …
73Special relativity — (SR) (also known as the special theory of relativity or STR) is the physical theory of measurement in inertial frames of reference proposed in 1905 by Albert Einstein (after considerable contributions of Hendrik Lorentz and Henri Poincaré) in the …
74Ohm's law — This article is about the law related to electricity. For other uses, see Ohm s acoustic law. V, I, and R, the parameters of Ohm s law. Ohm s law states that the current through a conductor between two points is directly proportional to the… …
75Gauge theory — For a generally accessible and less technical introduction to the topic, see Introduction to gauge theory. In physics, a gauge theory is a type of field theory in which the Lagrangian is invariant under a continuous group of local transformations …
76Momentum — This article is about momentum in physics. For other uses, see Momentum (disambiguation). Classical mechanics Newton s Second Law …
77Classical electromagnetism — Electromagnetism Electricity · …
78Surface integral — In mathematics, a surface integral is a definite integral taken over a surface (which may be a curved set in space); it can be thought of as the double integral analog of the line integral. Given a surface, one may integrate over it scalar fields …
79Wireless energy transfer — or wireless power is the transmission of electrical energy from a power source to an electrical load without artificial interconnecting conductors. Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous,… …
80Reciprocity (electromagnetism) — This page is about reciprocity theorems in classical electromagnetism. See also Reciprocity (mathematics) for unrelated reciprocity theorems, and Reciprocity for more general usages of the term. In classical electromagnetism, reciprocity refers… …
