Which unit is used to indicate a value of power?

The unit used to indicate a value of power is the Watt. Power, in the context of electrical systems, is defined as the rate at which energy is transferred or converted. In electrical terms, it can be understood as the product of voltage (volts) and current (amperes). The Watt quantitatively expresses this relationship, signifying how much energy is used or produced in a given time period.

The relevance of the Watt in practical applications can't be understated; it's the standard unit utilized in both residential and industrial settings to measure the consumption of electrical energy, allowing consumers to understand their energy usage on utility bills, for instance.

The other choices correspond to different electrical units: Voltage is indicated by the Volt, which measures electric potential; Frequency is indicated by Hertz, which measures cycles per second in a waveform; and Resistance is indicated by the Ohm, which measures how much a material opposes the flow of electric current. Each of these units serves its own critical role in the field of electronics and electricity but does not measure power directly.