The unit that measures the power output of a light bulb is which?

The unit that measures the power output of a light bulb is which?

• A. Volts
• B. Ohms
• C. Watts
• D. Amperes

Answer: (C)

Power is the rate at which energy is used or produced, and in electricity this rate is measured in watts. The idea comes from the formula P = V × I, where power equals voltage (the push behind the current) times current (the flow of charge). A light bulb’s power rating reflects how much energy per second it consumes, which is exactly what watts quantify. Volts describe potential difference, the pushing force behind current, but not how much energy per second is used. Ohms describe resistance, how strongly a device opposes current, which influences current for a given voltage but isn’t a measure of energy transfer itself. Amperes measure current, the amount of charge flowing per unit time, but not the energy rate. So the unit that directly measures the power output is watts.

Power is the rate at which energy is used or produced, and in electricity this rate is measured in watts. The idea comes from the formula P = V × I, where power equals voltage (the push behind the current) times current (the flow of charge). A light bulb’s power rating reflects how much energy per second it consumes, which is exactly what watts quantify.

Volts describe potential difference, the pushing force behind current, but not how much energy per second is used. Ohms describe resistance, how strongly a device opposes current, which influences current for a given voltage but isn’t a measure of energy transfer itself. Amperes measure current, the amount of charge flowing per unit time, but not the energy rate. So the unit that directly measures the power output is watts.