Which statement correctly defines power in a DC circuit?

Which statement correctly defines power in a DC circuit?

• A. Power dissipated equals current squared times resistance
• B. Power equals voltage divided by resistance
• C. Power equals applied voltage times current
• D. Power equals voltage plus current

Answer: (C)

Power is the rate at which electrical energy is transferred or converted in a circuit. In a DC circuit, the general definition is P = V × I, meaning you multiply the voltage across an element by the current through it. This form works for any element, not just resistors, making it the universal way to define power in a DC circuit. If the element is a resistor, you can also express power using I^2R or V^2/R, since V = IR applies there. But those are specific forms that rely on Ohm's law for a resistor; they’re not universal definitions of power for all circuit elements. Dividing voltage by resistance would give current, not power, and adding voltage and current isn’t a valid way to define power.

Power is the rate at which electrical energy is transferred or converted in a circuit. In a DC circuit, the general definition is P = V × I, meaning you multiply the voltage across an element by the current through it. This form works for any element, not just resistors, making it the universal way to define power in a DC circuit.

If the element is a resistor, you can also express power using I^2R or V^2/R, since V = IR applies there. But those are specific forms that rely on Ohm's law for a resistor; they’re not universal definitions of power for all circuit elements.

Dividing voltage by resistance would give current, not power, and adding voltage and current isn’t a valid way to define power.