What is the approximate voltage drop across the 20-ohm coil in the series arrangement described above?

• A. About 2.18 V
• B. About 21.82 V
• C. 24 V
• D. 0 V

Answer: (A)

In a series circuit, the same current flows through every component, and the voltage across each part is proportional to its resistance. The voltage across the 20-ohm coil is found by multiplying the circuit current by its resistance: V = I × 20. The current in this setup is determined by the total resistance and the 24 V supply. If the total resistance is about 220 ohms, the current is roughly 0.109 A, giving a voltage drop across the 20-ohm coil of 0.109 × 20 ≈ 2.18 V. The remaining voltage (about 21.82 V) drops across the other components in the series. Therefore, the approximate voltage drop across the 20-ohm coil is about 2.18 V.