This browser experiment examines the consequences of an ideal two-resistor circuit model. It provides calculated values as the inputs change, including the effect of a resistive load. The companion article develops the circuit equations; this page records the tool's assumptions and how to use its outputs.
Inputs and interpretation
Set the input voltage, upper resistance \(R_1\), and lower resistance \(R_2\). The circuit diagram locates \(R_1\) between the input and output, and \(R_2\) between the output and ground. Use the units shown by the controls when entering values.
Enable the optional load to add a resistance between the output and ground. The tool calculates both the unloaded output and the loaded output, then reports current through \(R_1\) and the output fraction. That current is the total input current: with a load connected it splits between the lower resistor and the load.
The tolerance selector offers 0%, 1%, 5%, and 10%. Its interval represents extreme combinations of the two divider resistances. It holds the input voltage and load resistance fixed, so the interval does not include uncertainty in those values.
| Output | Interpretation |
|---|---|
| Unloaded voltage | Ideal divider with no connected load |
| Loaded voltage | Ideal divider with the chosen parallel load |
| Input current | Current through the upper resistor |
| Output fraction | Output expressed relative to the input |
| Tolerance range | Lowest and highest outputs at divider-resistor extremes |
Method and checks
The calculator first replaces the lower resistor and load with their equivalent parallel resistance, when the load is enabled. It then applies the ideal series-divider relation. Resistor tolerance is handled by evaluating the corners of the allowed \(R_1\) and \(R_2\) ranges and retaining the smallest and largest output.
Several simple cases make the outputs easy to inspect. Equal divider resistances should give half the input voltage with no load. Multiplying both by the same factor should preserve that voltage while changing the current. Enabling a finite positive load should lower the output for a positive input voltage. Selecting 0% tolerance should collapse the displayed range to the calculated output.
These checks examine the implemented model; they are not substitutes for comparing a real circuit with a meter or oscilloscope.
Scope of the artifact
No hardware is connected, and no measured data is used. Every displayed result is a deterministic calculation from the entered values. Changing the inputs produces another prediction of the same model rather than a new observation.
The model assumes positive, ideal resistances and a source that maintains the selected input voltage. It omits input-source resistance, changing or reactive loads, temperature behaviour, component power ratings, and manufacturing distributions. The tolerance range is a worst-case bound under these assumptions; it is not a confidence interval.
The completed artifact is a small educational circuit calculator. A physical build, measured comparison, or sensor experiment would need its own component details, instruments, operating conditions, and observations before being documented as an experimental result.