What is the formula for power in a DC circuit?

What is the formula for power in a DC circuit?

• A. Voltage x Current
• B. Current x Resistance
• C. Voltage x Capacitance
• D. Power x Time

Answer: (A)

Power in a DC circuit is the rate at which electrical energy is transferred, and it is found by multiplying the supply voltage by the current: P = V × I. This tells you how much energy per second the circuit delivers or absorbs. In DC, V and I are typically constant, so this product gives a steady power value. You can also connect this to Ohm's law: since V = IR, you can write P = VI = I(IR) = I²R or P = V²/R, which shows how power relates to resistance or voltage when current or voltage is known. The other expressions don’t represent power. Current times resistance yields voltage, not power, so it’s not a measure of power. Voltage times capacitance isn’t a standard power expression. And multiplying power by time would give energy, not power. If you know a 12-volt supply delivering 2 amperes, the power is 24 watts.

Power in a DC circuit is the rate at which electrical energy is transferred, and it is found by multiplying the supply voltage by the current: P = V × I. This tells you how much energy per second the circuit delivers or absorbs. In DC, V and I are typically constant, so this product gives a steady power value. You can also connect this to Ohm's law: since V = IR, you can write P = VI = I(IR) = I²R or P = V²/R, which shows how power relates to resistance or voltage when current or voltage is known.

The other expressions don’t represent power. Current times resistance yields voltage, not power, so it’s not a measure of power. Voltage times capacitance isn’t a standard power expression. And multiplying power by time would give energy, not power. If you know a 12-volt supply delivering 2 amperes, the power is 24 watts.