Question

What is electric power and how is it calculated?

Answer 1

Electric power refers to the rate at which electrical energy is transferred or consumed in an electrical circuit. It's a measure of how quickly electric energy is converted from one form to another, usually from electrical potential energy (voltage) to other forms like light, heat, or mechanical motion. Electric power is typically measured in watts (W).

The formula to calculate electric power is:

Power (P) = Voltage (V) × Current (I)

Where:

Power (P) is measured in watts (W)
Voltage (V) is the potential difference or electrical pressure measured in volts (V)
Current (I) is the flow of electric charge measured in amperes (A)

This formula is derived from the fundamental relationship between voltage, current, and power known as Ohm's Law:

Voltage (V) = Current (I) × Resistance (R)

Substituting the value of voltage from Ohm's Law into the power formula gives us:

Power (P) = (Current (I) × Resistance (R)) × Current (I) = Current (I)^2 × Resistance (R)

So, there are two common formulas for calculating electric power:

Power (P) = Voltage (V) × Current (I)
Power (P) = Current (I)^2 × Resistance (R)

These formulas are used to calculate the power consumed or produced in various electrical devices and systems, helping us understand how efficiently energy is being utilized or transformed within an electrical circuit.