These are equations and variables used in this study. The physical quantity used in electromagnetism is calculated as a variable. Equations 1 and 2 represent the potential obtained from Maxwell's equations, the sources of which are charge and current. In addition, the relationship between current and charge is expressed using continuous equation in Eq.3, and the relationship between potential and current is expressed using Ohm's law in Eq. 4. By solving these equations simultaneously, phenomena in the circuit can be described.