Current Kvl
1. **State the problem:**
Find the current through the 8 ohm resistor in a circuit containing resistors of 7 ohms, 12 ohms, and 8 ohms, and two batteries of 20V and 15V, using Kirchhoff's Voltage Law (KVL).
2. **Set up the circuit loop and assume loop current:**
Assume a single loop with current $I$ flowing clockwise through all resistors.
3. **Write the KVL equation:**
Sum of voltage rises and drops around the loop equals zero.
This includes battery voltages (+20V and -15V) and voltage drops across resistors using Ohm's law: $V=IR$.
$$20V - I \times 7 \Omega - I \times 12 \Omega - I \times 8 \Omega - 15V = 0$$
4. **Simplify the equation:**
Combine resistances: $7 + 12 + 8 = 27 \Omega$.
$$20 - 27I - 15 = 0$$
$$5 = 27I$$
5. **Solve for current $I$:**
$$I = \frac{5}{27}$$
6. **Calculate numerical value:**
$$I \approx 0.1852\text{ A}$$
**Final Answer:** The current through the 8 ohm resistor is approximately **0.185 A**.