Which formula gives power in a circuit using voltage and current?

Which formula gives power in a circuit using voltage and current?

• A. P = I × R
• B. P = V / I
• C. P = V^2 / R
• D. P = V × I

Answer: (D)

Power is the rate at which energy is transferred. When a circuit element has a voltage V across it and a current I flowing through it, the power is simply the product of those two quantities: P = V × I. This directly ties to the definition of electrical power and uses both voltage and current. From Ohm's law, V = IR, you can derive other valid forms like P = I²R or P = V²/R, but those involve only resistance or only one of the quantities in question. Among expressions given, the one that multiplies voltage by current uses both quantities and yields power in watts.

Power is the rate at which energy is transferred. When a circuit element has a voltage V across it and a current I flowing through it, the power is simply the product of those two quantities: P = V × I. This directly ties to the definition of electrical power and uses both voltage and current.

From Ohm's law, V = IR, you can derive other valid forms like P = I²R or P = V²/R, but those involve only resistance or only one of the quantities in question. Among expressions given, the one that multiplies voltage by current uses both quantities and yields power in watts.