Power is measured in what unit?

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

Answer: (B)

Power is the rate at which energy is transferred or transformed in a system. In electrical contexts, it tells you how quickly electrical energy is doing work or being consumed. The unit for power is the watt, named after James Watt. One watt equals one joule per second, so watts measure how fast energy is being used. That makes watts the natural answer when the question asks for the unit of power.

Volts measure electrical potential difference, not power. Ohms measure resistance. Joules measure energy or work done, not the rate of energy transfer. For larger electrical loads, you’ll also see kilowatts, where 1 kilowatt equals 1000 watts.