免费欧姆定律计算器

使用欧姆定律计算电压、电流和电阻的关系。

V
A

电阻

24.00 Ω

功率6.000 W

Resistance vs Voltage

公式

How Ohm's Law Works

Ohm's Law links voltage, current, and resistance.

Formula

V = I x R

Where:

  • V = Voltage in volts
  • I = Current in amperes
  • R = Resistance in ohms
  • Rearranging gives R = V / I and I = V / R. Power is P = V x I.

    计算示例

    A 12 V battery drives 0.5 A through a resistor.

    1. 01Resistance R = V / I = 12 / 0.5 = 24 ohms
    2. 02Power P = V x I = 12 x 0.5 = 6 W

    常见问题

    What is Ohm's Law?

    Ohm's Law states that current is proportional to voltage and inversely proportional to resistance: V = I x R.

    When does Ohm's Law not apply?

    It does not apply to nonlinear devices like diodes and transistors where resistance changes with voltage or current.

    How do I find current if I know voltage and resistance?

    Rearrange to I = V / R. For example, 12 V across 24 ohms gives 0.5 A.

    学习

    Ohm's Law Guide

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