/ˈpaʊər/
noun … “Rate of doing work or transferring energy.”
Power in electrical systems is the rate at which energy is transferred or converted by an electrical circuit. It is determined by the product of voltage and current, representing how much work is being done per unit time. Power is a critical measure for sizing circuits, selecting components, and understanding energy consumption.
Key characteristics of Power include:
- Unit: measured in watts (W), where 1 W = 1 V × 1 A.
- DC power: P = V × I, with voltage and current constant over time.
- AC power: can include real, reactive, and apparent power, depending on phase difference between voltage and current.
- Energy relation: total energy consumed over time is the integral of power (E = ∫ P dt).
- Heat and work: power determines how quickly energy is delivered to loads, producing motion, light, or heat.
Applications of Power include electrical appliances, motors, lighting, batteries, and energy management systems.
Workflow example: Calculating power in a DC circuit:
voltage = 12 -- volts
current = 2 -- amperes
power = voltage * current
print(power) -- 24 W
Here, the circuit delivers 24 watts of power, converting electrical energy into useful work or heat.
Conceptually, Power is like the strength of a river: it measures how much water (energy) flows through per second to do work on a waterwheel.
See Voltage, Current, Resistance, Energy, Electricity.