Question: Which of the following is conserved in Kirchhoff’s first law?
A Voltage
B Current
C Resistance
D Charge
Answer: Charge
| Aspect | Description |
| Kirchhoff’s First Law | Also Known As Kirchhoff’s Current Law (KCL) |
| Basic Principle | · The sum of all currents entering a node (or junction) in an electrical circuit is equal to the sum of all currents leaving the node.
· It is based on the conservation of charge. |
| Mathematical Expression | ΣI_in = ΣI_out (The sum of currents entering a node equals the sum of currents leaving the same node.) |
| Application | Used to analyze and solve complex electrical circuits by ensuring that current is conserved at every junction or node. |
| Conservation Principle | According to this law, no charge is lost within the node; all charge that enters must leave. |
| Sign Convention | · Currents entering the node are typically considered positive.
· Currents leaving the node are considered negative. |
| Usage | Helps in the calculation of unknown currents in various parts of a circuit. |