Let us first discuss the Maxwell equations. In this, let us first derive and discuss Maxwell fourth equation:

**1. Maxwell’s Fourth Equation or Modified Ampere’s Circuital Law**

Here the first question arises , **why there was need to modify Ampere’s circuital Law?**

To give answer to this question, let us first discuss Ampere’s law(without modification)

**Statement of Ampere’s circuital law (without modification).** It states that the line integral of the magnetic field H around any closed path or circuit is equal to the current enclosed by the path. Continue reading “Maxwell’s Equations and their derivations”