What is Electrical Power?

 

Introduction

What is electrical power? Have you ever been curious? In this article, we’ll cover the basics of electric power.

Definition of electric power

Electric power is the speed at which electricity is used, indicating the amount of work done by the current at a given time, which simply means how fast an electric device consumes energy while it is working.

Formula for Electric Power

In the electric power formula, electric power is expressed as P in watts (W), and the following are common formulas about electric power.

1. Basic formula

The formula for calculating electric power is:

\(P =\frac {W}{t}\)Where

– W: expressed as electrical work, the unit is joule (J);

– t: expressed as time, the unit is seconds (s).

2. Combined with the extension of Ohm’s law formula

Known voltage and current, the formula is:

\(P =U \cdot I\)where

– U: is the voltage in volts (V). For the same resistance, an increase in voltage will allow the current to increase, making the power higher.

– I: is expressed as current in amperes (A). At the same voltage, an increase in current raises the power.

The current and resistance are known, and the formula is:

\(P = I^2 \cdot R\)With known voltage and resistance, the formula is:

\(P =\frac {U^2}{R}\)where

– R: denotes resistance in ohms (Ω). When the current is fixed, the higher the resistance, the higher the power. When the voltage is fixed, the lower the resistance, the higher the power.

Application of electric power

The electric power mentioned above is all about the expression on the formula, here we say what role electric power plays in our life.

1. Household electricity: the electric rate of the lamp determines its brightness; and the electric power of the air conditioner affects the speed of refrigeration.
2. Industrial production equipment: machines with more power run faster and produce at a higher rate.
3. Daily transportation: The power variation of an electric car determines its speed and load capacity.