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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.

Công thức

V = IR · P = IV = I²R = V²/R

Hướng dẫn từng bước

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

Ví dụ có lời giải

đầu vào

V = 12V · R = 47Ω

Kết quả

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

Lỗi thường gặp cần tránh

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

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