In previous article I have explain Ohm’s Law for DC circuit but only Ohm’s Law is not sufficient to understand voltage and current in complex circuit. So here in this article I am trying to explain Kirchhoff’s Law for complex circuit.
In 1845, a German physicist, Gustav Kirchhoff found out some method to calculate voltage, Current & Resistance in any complex circuit. Now these methods are called Kirchhoff Law. It can further divided in 2 parts.
- Kirchhoff Current Law (KCL)
- Kirchhoff Voltage Law (KVL)
Here the important thing is that, Kirchhoff’s Law only works on Closed Circuit. If circuit is open or any branch of circuit is open, it will not work.
Related Article: Understanding Ohm’s Law in DC circuit
Kirchhoff’s Current Law, (KCL)
According to this Law, in any node, total charge entering in the node is equivalent to the charge leaving from that node. It is also known as the Law of “Conservation of Charge”.
In mathematical terms, algebraic sum of all current (entering or leaving) in node is equivalent to the Zero.
As per figure, I1, I2 & I3 is “IN Current” and I4 & I5 is “OUT Current”.
Here, the three currents I1, I2 & I3 are considered positive in value and I4 and I5 are considered negative in value. So the final equation will be;
I1 + I2 + I3 – I4 – I5 = 0
Kirchhoff’s current law is also known as Kirchhoff’s first law.
Note: In circuit node is a junction where two or more current carrying branches are connected.
Kirchhoff’s Voltage Law, (KVL)
As per this law, “In any closed loop circuit or network, total applied voltage is equal to total drop in voltage”. In other word algebraic sum of all voltages is equal to zero.
It is based on “Conservation of Energy”. As per figure
Application of Kirchhoff’s Circuit Laws
Kirchhoff’s Current Law and Voltage Law are very fundamental laws in electronic. By using these laws we can easily understand circuit behavior and also find value of any unknown element.
Circuit – It is an arrangement where current flows. In other words it is a close path with electronic component such as resistor, battery etc.
Node – It is a junction point of two or more than two paths.
you can also visit wikipedia for more clarification.