A watt is defined as a joule per:

A watt is defined as a joule per second, which means it measures the rate of energy transfer or conversion. In this context, a joule is the unit of energy, and a second serves as the time interval over which this energy transfer occurs. Therefore, when one joule of energy is used or produced in one second, the power output or consumption is one watt. This definition is fundamental in electricity and electronics because it establishes the relationship between energy, time, and power, making it a crucial concept for understanding electrical systems and their efficiency.

Other options such as minute, hour, or cycle do not accurately reflect the standard unit of power measurement in the International System of Units (SI). While energy can be measured over longer time spans like minutes or hours, these units do not provide the immediate rate of power output that a second does. Similarly, cycles pertain more to frequency in alternating current systems rather than directly relating energy to time in the context of power measurement.