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CALC 03 · BASICFREE

Voltage/Current Divider

INPUT PARAMETERS
V
Ω
Ω
CALCULATION SHEET
Output Voltage (unloaded)
8.000 V
I = 4.000 mA · P_total = 48.000 mW
Steps
  1. 01Model: unloaded ideal divider — nothing is connected across Vout. A load R_L across R2 puts R2 ∥ R_L in the formula and lowers Vout.
  2. 02Voltage Divider Formula: Vout = (R2 / (R1 + R2)) × Vin
  3. 03Vout = (2000 / (1000 + 2000)) × 12
  4. 04Vout = (2000 / 3000) × 12
  5. 05Vout = 8.000 V
  6. 06Total resistance: Rt = R1 + R2 = 1000 + 2000 = 3000 Ω
  7. 07Current: I = Vin / Rt = 12 / 3000 = 0.004000 A
  8. 08Power in R1: P1 = I² × R1 = 0.004000² × 1000 = 0.016 W
  9. 09Power in R2: P2 = I² × R2 = 0.004000² × 2000 = 0.032 W
  10. 10Total power: Pt = P1 + P2 = 0.016 + 0.032 = 0.048 W
  11. 11Voltage ratio: Vout / Vin = 0.6667 (66.7%)
REFERENCE — FORMULAS
Voltage Divider (unloaded):
V_out = V_in × (R₂ / (R₁ + R₂))

Assumes nothing is connected across V_out. A load R_L in parallel with R₂ replaces R₂ with R₂ ∥ R_L in the formula and lowers V_out — this page does not model a load.

Current Divider (two branches):
I₁ = I_in × (R₂ / (R₁ + R₂))
I₂ = I_in × (R₁ / (R₁ + R₂))

The smaller resistor carries the larger share of the current. Both branches see the same voltage.