Which formula represents electrical power?

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Multiple Choice

Which formula represents electrical power?

Power in an electrical circuit is the rate at which energy is delivered to a device. It depends on both how strong the push is (voltage) and how much charge flows per second (current). The direct way to find this rate is to multiply voltage by current: P = V × I, which gives power in watts. For example, if the voltage is 10 volts and 2 amperes flow, the power is 10 × 2 = 20 watts. Other forms don’t represent power in general: multiplying current by resistance gives a quantity with voltage units, not power; V^2 ÷ I isn’t the standard expression for power; and V ÷ R gives current, not power. You can derive other equivalent forms of power using Ohm’s law, such as P = I^2R or P = V^2/R, but the straightforward and universally correct expression is P = VI.

Power in an electrical circuit is the rate at which energy is delivered to a device. It depends on both how strong the push is (voltage) and how much charge flows per second (current). The direct way to find this rate is to multiply voltage by current: P = V × I, which gives power in watts.

For example, if the voltage is 10 volts and 2 amperes flow, the power is 10 × 2 = 20 watts.

Other forms don’t represent power in general: multiplying current by resistance gives a quantity with voltage units, not power; V^2 ÷ I isn’t the standard expression for power; and V ÷ R gives current, not power. You can derive other equivalent forms of power using Ohm’s law, such as P = I^2R or P = V^2/R, but the straightforward and universally correct expression is P = VI.

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