Uniform series current: a series circuit has a 24 V source and a total resistance of 120 Ω. What is the current through each resistor (same for all in series)?

Introduction / Context:
In a series circuit, there is only one path, so the same current flows through all components. Calculating that current from the source voltage and total resistance is a direct application of Ohm’s law and sets the current for every series element simultaneously.

Given Data / Assumptions:

• Source voltage: 24 V.
• Total series resistance: 120 Ω.
• Ideal circuit elements and steady-state DC.

Concept / Approach:

Apply Ohm’s law to the entire series combination: I = V / R_total. The resulting current is the same through each series resistor, regardless of individual values.

Step-by-Step Solution:

Verification / Alternative check:

Power check: P_total = V * I = 24 * 0.2 = 4.8 W; consistent with I^2 * R_total = 0.2^2 * 120 = 4.8 W.

Why Other Options Are Wrong:

24 mA and 20 mA are an order of magnitude too small; 120 mA corresponds to 0.12 A, not supported by 24/120.

Common Pitfalls:

Accidentally dividing the current among series resistors as if they were parallel; misplacing decimal points during conversion to mA.

Final Answer:

200 mA