1. **Problem statement:** Find the currents $I_1$, $I_2$, and $I_3$ in the given circuit using Kirchhoff's laws.
2. **Identify the loops and junctions:**
- Junction at point $b$: currents satisfy $I_1 = I_2 + I_3$ (Kirchhoff's Current Law).
- Loop 1: $f \to a \to b \to e \to f$ (left loop with 32V battery and 2\Omega and 8\Omega resistors).
- Loop 2: $b \to c \to d \to e \to b$ (right loop with 4\Omega resistor and 20V battery).
3. **Write Kirchhoff's Voltage Law (KVL) equations for each loop:**
- Loop 1 (clockwise):
$$32 - 2I_1 - 8I_3 = 0$$
- Loop 2 (clockwise):
$$4I_2 - 20 + 8I_3 = 0$$
4. **Use the junction equation:**
$$I_1 = I_2 + I_3$$
5. **Substitute $I_1$ from junction into Loop 1 equation:**
$$32 - 2(I_2 + I_3) - 8I_3 = 0$$
$$32 - 2I_2 - 2I_3 - 8I_3 = 0$$
$$32 - 2I_2 - 10I_3 = 0$$
6. **Rewrite Loop 2 equation:**
$$4I_2 - 20 + 8I_3 = 0$$
$$4I_2 + 8I_3 = 20$$
7. **Now solve the system:**
From Loop 1:
$$2I_2 + 10I_3 = 32$$
From Loop 2:
$$4I_2 + 8I_3 = 20$$
8. **Multiply Loop 1 equation by 2 to align $I_2$ coefficients:**
$$4I_2 + 20I_3 = 64$$
9. **Subtract Loop 2 equation from this:**
$$ (4I_2 + 20I_3) - (4I_2 + 8I_3) = 64 - 20$$
$$ 12I_3 = 44$$
$$ I_3 = \frac{44}{12} = \frac{11}{3} \approx 3.67 \text{ A}$$
10. **Substitute $I_3$ back into Loop 2 equation:**
$$4I_2 + 8 \times \frac{11}{3} = 20$$
$$4I_2 + \frac{88}{3} = 20$$
$$4I_2 = 20 - \frac{88}{3} = \frac{60}{3} - \frac{88}{3} = -\frac{28}{3}$$
$$I_2 = -\frac{28}{12} = -\frac{7}{3} \approx -2.33 \text{ A}$$
11. **Find $I_1$ using junction equation:**
$$I_1 = I_2 + I_3 = -\frac{7}{3} + \frac{11}{3} = \frac{4}{3} \approx 1.33 \text{ A}$$
12. **Interpretation:**
- $I_1 \approx 1.33$ A flows from left to right.
- $I_2 \approx -2.33$ A means current $I_2$ flows opposite to assumed direction.
- $I_3 \approx 3.67$ A flows downward as assumed.
**Final answers:**
$$I_1 = \frac{4}{3} \text{ A}, \quad I_2 = -\frac{7}{3} \text{ A}, \quad I_3 = \frac{11}{3} \text{ A}$$
Kirchhoff Currents 6Bfe27
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.