Electrical Engineering
Circuit Builder
Build resistive, reactive, or rectifier circuits. Get a full breakdown of voltage, current, impedance, and power for every component.
Schematic
Yellow = voltage drop · Red arrow = conventional current (+ to −) · Tag colour: white=R, cyan=C, purple=L, orange=D
Circuit Builder
Voltage Source
Analysis
383.3 Ω
Total Resistance
31.30 m A
Total Current
375.7 m W
Total Power
12 V
Source
Voltage Distribution
Component Breakdown
| Part | R / Ω | V drop | Current | Power | Status |
|---|---|---|---|---|---|
| R1 | 100 Ω | 3.13 V | 31.30 m A | 98.00 m W | active |
| R2 | 200 Ω | 4.174 V | 20.87 m A | 87.11 m W | active |
| R3 | 400 Ω | 4.174 V | 10.43 m A | 43.55 m W | active |
| R4 | 150 Ω | 4.696 V | 31.30 m A | 147.0 m W | active |
KVL Check
ΣV drops = 12 V = 12 V ✓
What's happening
R1 and R4 are in series with the source; R2 and R3 sit in parallel between them.
Resistor (R)
A resistor limits current and drops voltage proportional to its resistance (V = I × R, Ohm's Law). Combining them in different topologies lets you achieve any target resistance or voltage distribution.
To analyze this, collapse the parallel group first: R2 ‖ R3 = (200 × 400) / (200 + 400) ≈ 133 Ω. Now the circuit is just three resistors in series: R1 + R_parallel + R4 = 100 + 133 + 150 = 383 Ω.
The same current flows through R1 and R4 (series path), so they drop voltage proportional to their resistance. Inside the parallel group, both R2 and R3 see the same voltage — but R2 (lower resistance) carries more current than R3.
This combination is extremely common in real designs. For example, a series resistor might set the total current for a circuit, while a parallel pair provides two paths to ground for different sub-circuits.