Series–parallel in practice: A “loaded voltage divider” (a resistor divider that feeds a finite load) is a common and important application of series–parallel circuits. Determine whether this usage description is accurate.

Introduction / Context:
Many real circuits use resistor dividers to derive reference or bias voltages. The moment a load is attached to a divider output, the circuit becomes a series–parallel network: the lower divider resistor is effectively in parallel with the load. Recognizing this is essential for predicting output sag and source current changes.

Given Data / Assumptions:

• Two-resistor divider from a DC supply.
• Finite load R_L from the divider output to ground.
• Resistive behavior; frequency effects ignored.

Concept / Approach:
With a load present, the bottom leg and R_L form a parallel combination. The output voltage becomes V_out = V_in * (R_bottom || R_L) / (R_top + (R_bottom || R_L)). This is a textbook series–parallel transformation and a standard example used to introduce loading effects in basic circuit courses.

Step-by-Step Solution:

Verification / Alternative check:
Measure V_out with and without the load; the loaded case is lower, matching the series–parallel formula prediction.

Why Other Options Are Wrong:

• Incorrect / only large load / low-voltage only / AC only: The classification as series–parallel does not depend on voltage level or frequency for resistive circuits and holds for any finite load.

Common Pitfalls:
Designing a divider without considering R_L, leading to excessive voltage sag or wasted current; forgetting to buffer the divider with an op-amp follower when a stiff source is required.

Final Answer:
Correct