Kirchhoff’s Laws

Kirchhoff’s current law and voltage law, defined by Gustav Kirchhoff, describe the relation of values of currents that flow through a junction point and voltages in an electrical circuit loop, in an electrical circuit. Kirchhoff’s Current Law (KCL) This is Kirchhoff’s first law. The sum of all currents that enter an electrical circuit junction is 0. The currents enter the junction have the positive sign and the currents that leave the junction have a negative sign:     Another way to look at this law is that the sum of…

Voltage Divider

Voltage divider rule finds the voltage over a load in the electrical circuit, when the loads are connected in series. Voltage divider rule for DC circuit For a DC circuit with constant voltage source VT and resistors in series, the voltage drop Vi in resistor Ri is given by the formula:   Vi – voltage drop in resistor Ri in volts [V]. VT – the equivalent voltage source or voltage drop in volts [V]. Ri – resistance of resistor Ri in ohms [Ω]. R1 – resistance of resistor R1 in ohms [Ω]. R2 – resistance of resistor R2 in ohms [Ω]. R3 – resistance of resistor R3 in…

Coulomb’s Law

Coulomb’s law formula Coulomb’s law calculates the electric force F in newtons (N) between two electric chargesq1 and q2 in coulombs (C) with a distance of r in meters (m):   F is the force on q1 and q2 measured in newtons (N). k is Coulomb’s constant k = 8.988×109 N⋅m2/C2 q1 is the first charge in coulombs (C). q2 is the second charge in coulombs (C). r is the distance between the 2 charges in meters (m). When charges q1 and q2 is increased, the force F is increased. When distance r is increased, the force F is decreased. Coulomb’s law example Find the force between 2 electric…