Which of the following is the formula for electrical power using resistance?

The formula for electrical power in terms of current and resistance is given by ( P = I^2R ). This expression indicates that the power ( P ), measured in watts (W), is equal to the square of the current ( I ) (in amperes) multiplied by the resistance ( R ) (in ohms). This relationship arises from Ohm’s law, which states that ( V = IR ), where ( V ) is the voltage. By rewriting the power formula ( P = IV ) and substituting for ( V ) using Ohm’s law, you can derive the power formula as follows:

1. Start with ( P = IV ).
2. Substitute ( V ) with ( IR ): ( P = I(IR) = I^2R ).

This shows that the power is directly proportional to the square of the current and the resistance. Therefore, as either current increases (while keeping resistance constant) or resistance increases (while keeping current constant), the power consumption will also increase significantly. This understanding is crucial in applications involving electrical circuits, as it helps in designing systems that manage power efficiently and safely.