Power in a circuit can be determined by

• A. Multiplying Current By Voltage
• B. Dividing voltage by current
• C. Dividing current by resistance
• D. Multiplying current by resistance

Answer: (A)

Power is the rate at which electrical energy is transferred in a circuit. The fundamental relationship is P = V × I, so you determine power by multiplying the circuit’s voltage by its current. This makes intuitive sense: the voltage provides the driving force that moves charges, and the current tells you how much charge is moving each second; together they quantify how much energy is delivered per second, i.e., power. In resistive or DC circuits you can also derive P = I^2R or P = V^2/R from Ohm’s law, reinforcing that power comes from the interaction of voltage and current with the circuit’s resistance.

Dividing voltage by current would give impedance (a measure of opposition to current), not power. Dividing current by resistance isn’t a standard way to express power, and multiplying current by resistance gives voltage (V = IR), not power. For a numeric example, 120 V with 2 A flows yields 240 watts of power.