Maxwell's Equation

Equation (5.1) and (5.2) gives the relationship among the field quantities in the static field. For time varying case, the relationship among the field vectors written as

                  (5.20a)

                        (5.20b)

                           (5.20c)

                            (5.20d)

In addition, from the principle of conservation of charges we get the equation of continuity

                                                                                        (5.21)
The equation 5.20 (a) - (d) must be consistent with equation (5.21).