How Do You Calculate Power From Voltage?
Voltage (measured in volts) is a difference of electric potentials that is a driving force of the electric current. The electric power (in watts) is a rate at which the energy is transferred in the electric circuit. According to the Joule’s law, the power is a function of the voltage and the electric current (in amperes). Also, it can be calculated using the voltage and the electrical resistance (in ohms). Obtain either voltage and current values or voltage and resistance ones to calculate the electric power. As an example, consider two sets of values: voltage, 200 volts; current, 1.4 amperes; and voltage, 127 volts; resistance, 150 ohms. Calculate the power from the voltage and the current using Joule’s law: Power = Voltage x Current In our example: Power = 200 volts x 1.4 amperes = 280 watts. Calculate the power from voltage and the resistance using Joule’s and Ohm’s laws. Ohm’s law states: Current = Voltage / Resistance Combining it with the Joule’s law (Step 2), you get: Power = (V
