In a series circuit, to find total resistance you:

In a series circuit, to find total resistance you:

• A. Multiply the resistances
• B. Subtract the smallest from the largest
• C. Add the resistances
• D. Divide by the number of resistors

Answer: (C)

In a series circuit, the same current flows through every component, so the total resistance is the sum of each resistor’s resistance. This comes from Ohm’s law: the total voltage equals the current times the total resistance, and each resistor drops a voltage V_i = I × R_i. Since the current I is the same through all resistors, the total voltage is I × (R1 + R2 + ...). Hence, the overall resistance seen by the source is R_total = R1 + R2 + …. That’s why you add the resistances to find the total in a series arrangement. Multiplying, subtracting, or averaging wouldn’t reflect how the single current passes through each resistor in order.

In a series circuit, the same current flows through every component, so the total resistance is the sum of each resistor’s resistance. This comes from Ohm’s law: the total voltage equals the current times the total resistance, and each resistor drops a voltage V_i = I × R_i. Since the current I is the same through all resistors, the total voltage is I × (R1 + R2 + ...). Hence, the overall resistance seen by the source is R_total = R1 + R2 + ….

That’s why you add the resistances to find the total in a series arrangement. Multiplying, subtracting, or averaging wouldn’t reflect how the single current passes through each resistor in order.