DC Power formula

P = V X I . Here P is power in watts. V is voltage in volts. I is current in amps.

Power Formulas in DC Circuits

In simple DC Circuits i.e., electric circuits with DC power supply, the power formula is given below:

P = V × I

Power in resistive DC Circuits is just the product of voltage and current.

We can derive further Power formulas by applying Ohm’s Law. According to Ohm’s Law, the voltage in a circuit (or component) is a product of the resistance and the current.

V = I × R

So, if we use this equation in the above Power Formula, we get

P = V × (V/R) = V2/R

P = (I×R) × I = I2R

Depending on the available quantities, you can use one of the three power formulas for calculating DC Power.