What is the total resistance of a circuit that has a 50-ohm resistor, a 75-ohm resistor, and a 100-ohm resistor in series?

• A. 125 ohms
• B. 225 ohms
• C. 50 ohms
• D. 75 ohms

Answer: (B)

In a series circuit, the same current flows through every resistor and the voltages add, so the total resistance is just the sum of the individual resistances. Add them: 50 + 75 + 100 = 225 ohms. This is the total resistance for all three resistors in series.

The other numbers would come from using only two of them (50 + 75 = 125 ohms) or treating a single resistor alone (50 ohms or 75 ohms).