Question

The figure below shows a part of an electric circuit.

1. Apply Kirchhoff’s junction rule to the junction A to find current flowing through the 5Ω resistor.
2. Apply Kirchhoff’s loop rule to the loop ABDA to find current flowing through the 7Ω resistor.

Answer 1

(a) I₁ + I₂ = I

2 + I₂ = 5

I₂ = 5 − 2

∴ I₂ = 3A

(b) I₁ × 4 + I₃ × 7 = I₂ × 5

2 × 4 + I₃ × 7 = 3 × 5

7I₃ = 15 – 8 = 7

∴ I₃ = 1A