Final answer:
To find current in circuit branches, use Kirchhoff's rules, label currents and junctions, and apply the junction and loop rules to determine current values.
Step-by-step explanation:
To find the current through each branch of a circuit, we can follow a systematic approach using Kirchhoff's rules. For complex circuits, simple series-parallel analysis isn't sufficient, and Kirchhoff's rules become necessary. In applying Kirchhoff's rules, we begin by labeling each junction and assigning a direction to the current in each branch, as represented by currents I₁, I2, and I3. There is no harm in assuming a direction for the current because if the assumed direction is incorrect, the resulting value will be negative, indicating the actual direction is the opposite.
When measuring voltage across resistors and measuring current before and after each resistor or branch, we use a multimeter. The sum of the currents before the parallel branches should equal the sum of the currents after due to the junction rule, which states that the total current entering a junction must equal the total current leaving.
Lastly, we apply Kirchhoff's loop rule to define equations for each loop in the circuit, which helps in solving for the unknown currents.