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Ohm's Law relates voltage, current, and resistance in electrical circuits. This calculator solves for any one of the four quantities — voltage (V), current (I), resistance (R), or power (P) — given any two known values.

Fórmula

V = IR · P = IV = I²R = V²/R

Guia passo a passo

  1. 1Enter any two known values (V, I, R, or P)
  2. 2The calculator solves the remaining two using Ohm's Law and the power formula
  3. 3Results apply to DC circuits and to AC circuits at unity power factor

Exemplos resolvidos

Entrada
V = 12V · R = 47Ω
Resultado
I = 12/47 ≈ 0.255 A · P = 12 × 0.255 ≈ 3.06 W
A 1/4W resistor would overheat here — use at least a 1/2W rated part

Erros comuns a evitar

  • Applying Ohm's Law to non-linear components (diodes, transistors)
  • Forgetting unit prefixes: mA, kΩ, mW

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