1. **State the problem:** Find the currents $I_1$, $I_2$, and $I_3$ in the given circuit using Kirchhoff's laws.
2. **Identify the circuit elements and nodes:**
- Resistors: $2\Omega$ (between $a$ and $b$), $4\Omega$ (between $b$ and $c$), $8\Omega$ (between $b$ and $e$).
- Voltage sources: $32$ V (between $f$ and $a$), $20$ V (between $c$ and $d$).
- Currents: $I_1$ from $a$ to $b$, $I_2$ from $b$ to $c$, $I_3$ from $b$ to $e$.
3. **Apply Kirchhoff's Current Law (KCL) at node $b$:**
$$I_1 = I_2 + I_3$$
4. **Apply Kirchhoff's Voltage Law (KVL) to the left loop $f \to a \to b \to e \to f$:**
$$32 - 2I_1 - 8I_3 = 0$$
5. **Apply KVL to the right loop $b \to c \to d \to e \to b$:**
$$4I_2 + 20 - 8I_3 = 0$$
6. **Rewrite the equations:**
- From KCL: $$I_1 - I_2 - I_3 = 0$$
- Left loop: $$32 = 2I_1 + 8I_3$$
- Right loop: $$4I_2 + 20 = 8I_3$$
7. **Express $I_2$ from the right loop:**
$$4I_2 = 8I_3 - 20 \implies I_2 = \frac{8I_3 - 20}{4} = 2I_3 - 5$$
8. **Substitute $I_2$ into KCL:**
$$I_1 - (2I_3 - 5) - I_3 = 0 \implies I_1 - 2I_3 + 5 - I_3 = 0 \implies I_1 - 3I_3 + 5 = 0$$
9. **Express $I_1$ from above:**
$$I_1 = 3I_3 - 5$$
10. **Substitute $I_1$ into left loop equation:**
$$32 = 2(3I_3 - 5) + 8I_3 = 6I_3 - 10 + 8I_3 = 14I_3 - 10$$
11. **Solve for $I_3$:**
$$14I_3 = 42 \implies I_3 = 3$$
12. **Find $I_1$:**
$$I_1 = 3(3) - 5 = 9 - 5 = 4$$
13. **Find $I_2$:**
$$I_2 = 2(3) - 5 = 6 - 5 = 1$$
**Final answer:**
$$I_1 = 4\,A, \quad I_2 = 1\,A, \quad I_3 = 3\,A$$
Kirchhoff Currents 04B45D
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