Answer the following question given this paragraph:   The rate at which a device changes electric current to another form of energy is called electric power . The SI unit for power—including electric power—is the watt. A watt equals 1 joule of energy per second. High wattages are often expressed in kilowatts, where 1 kilowatt equals 1000 watts. The power of an electric device, such as a hair dryer, can be calculated if you know the voltage of the circuit and how much current the device receives. The following equation is used:.   Q: What unit of power is equal to 1 joule of energy per second?   A:
Pick your answer from:
 (a). hertz;
 (b). byte;
 (c). volt;
 (d). watt;
Answer:
(d).