What is Kirchhoff's second law?/K12 Physics

 KIRCHHOFF'S SECOND LAW:

Kirchhoff's second law is also known as VOLTAGE LAW (OR) LOOP LAW.This law is based on LAW OF CONSERVATION OF ENERGY.Kirchhoff's second law states that

 "THE ALGEBRAIC SUM OF ALL THE POTENTIAL DIFFERENCES ALONG A CLOSED LOOP IS ZERO".

CONVENTIONS:

Take any direction as the direction of traversal.(Either clockwise or anticlockise)

EMF of the cell is POSITIVE if the direction of the traversal is from its NEGATIVE terminal to POSITIVE terminal. (NPP)

EMF of the cell is NEGATIVE if the direction of the traversal is from its POSITIVE terminal to NEGATIVE terminal. (PNN)

The IR product is taken as POSITIVE if the resistor is traversed in the same direction as the assumed current.

Find the current in each wire using Kirchhoff’s voltage law (the second law)

SOLUTION: MODIFIED CIRCUIT          

The modified circuit is shown above. All elements are connected in series.Here we can select the direction of  traversal as anti-clockwise.In a series combination of the circuit,the current through all the components is the same.Consider the current through each element be I . Now we can apply Kirchhoff's second law.