Power is measured in what unit?

Power is measured in watts, which is the standard unit in the International System of Units (SI). It quantifies the rate at which energy is transferred or converted. In electrical systems, power can be defined as the product of voltage (in volts) and current (in amperes), illustrating the relationship between these units. Thus, when discussing the energy or work done over time—particularly in the context of lasers and their operation—watts become essential for understanding their performance and efficacy.

The other units listed (volts, amperes, and joules) pertain to different electrical and energy concepts. Volts measure electric potential difference, amperes quantify electric current, and joules represent energy. While all these units are related within the realm of physics and electricity, only watts specifically define power.