Electric power

P=UI=I^2R=\dfrac{U^2}{R}

Result unit: W (watt)

What it describes

The power dissipated by an electrical load.

P

power

[W]

U

voltage

[V]

I

current

[A]

R

resistance

[Ω]

The power of a load is the product of voltage and current. Knowing the resistance, it can be written as

I^2R

U^2/R

— convenient when you know

R

Heaters, light bulbs, selecting fuses and device power ratings.

A light bulb powered by 230 V draws 0.26 A. Calculate its power.

Substitution

U=230

I=0.26

Result

P=230\cdot0.26\approx60

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