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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.

Formula

V = IR · P = IV = I²R = V²/R

Guida passo passo

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

Esempi risolti

Ingresso

V = 12V · R = 47Ω

Risultato

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

Errori comuni da evitare

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

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