Kirchhoff's law should be followed to analyze a circuit.

Explanation:
Kirchhoff's law, also known as Kirchhoff's circuit laws or Kirchhoff's rules, are fundamental principles used to analyze electrical circuits. These laws are named after the German physicist Gustav Kirchhoff, who first described them in the mid-19th century. There are two Kirchhoff's laws, namely Kirchhoff's current law (KCL) and Kirchhoff's voltage law (KVL).

1. Kirchhoff's Current Law (KCL):
- KCL states that the algebraic sum of currents entering and leaving a junction (or node) in a circuit is zero.
- In other words, the total current flowing into a junction is equal to the total current flowing out of it.
- This law is based on the principle of conservation of charge, as no charge can be created or destroyed within a circuit.
- KCL can be used to determine unknown currents in a circuit and to verify the correctness of circuit analysis.

2. Kirchhoff's Voltage Law (KVL):
- KVL states that the algebraic sum of the potential differences (voltages) around any closed loop in a circuit is zero.
- In simpler terms, the sum of the voltage drops across all elements in a closed loop is equal to the sum of the voltage rises.
- This law is based on the principle of conservation of energy, as the total energy supplied by a source must be equal to the total energy consumed by the circuit elements.
- KVL can be used to determine unknown voltages in a circuit and to verify the correctness of circuit analysis.

Applying Kirchhoff's laws allows us to analyze complex circuits with multiple resistors, capacitors, inductors, and voltage/current sources. By using KCL and KVL, we can set up and solve a system of equations to determine the values of currents and voltages at different points in the circuit. This analysis is crucial for designing and troubleshooting electrical circuits in various applications, such as electronics, power systems, and telecommunications.

In conclusion, Kirchhoff's law, particularly Kirchhoff's current law (KCL) and Kirchhoff's voltage law (KVL), should be followed to analyze a circuit. These laws provide a systematic approach to solving circuit problems by applying the principles of charge conservation and energy conservation.