免费电功率计算器
计算电路中的功率P=VI。
Power (V*I)
600.0000 W
Power (V*I) vs Voltage
公式
## Electrical Power Electrical power is the rate of energy transfer in an electric circuit. ### Three Equivalent Forms **P = V * I** (voltage times current) **P = I² * R** (current squared times resistance) **P = V² / R** (voltage squared divided by resistance) All three yield the same result when V, I, and R satisfy Ohm's law.
计算示例
A 120 V circuit drawing 5 A through a 24 ohm load.
- 01P = V * I = 120 * 5 = 600 W
- 02P = I² * R = 25 * 24 = 600 W
- 03P = V² / R = 14400 / 24 = 600 W
常见问题
What is the difference between watts and kilowatt-hours?
Watts measure instantaneous power. Kilowatt-hours measure energy consumed over time: 1 kWh = 1000 W used for 1 hour.
How does power relate to heat in a resistor?
All electrical power in a resistor is converted to heat (Joule heating). P = I²R gives the heat dissipation rate.
What is the power of a typical household outlet?
In the US, a 120 V / 15 A outlet can deliver up to 1800 W. A 240 V / 30 A outlet delivers up to 7200 W.
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