Power Unit: Understanding Watts

Power is defined as the rate at which work is done or energy is transferred. Mathematically, it is expressed as:

$ \text{Power} = \frac{\text{Work}}{\text{Time}} $

The standard unit of work (or energy) is the Joule (J), and the standard unit of time is the second (s). Therefore, the unit of power is Joules per second (J/s).

By definition, one Joule per second is equivalent to one Watt (W).

$ 1 \, \text{Watt} = 1 \, \frac{\text{Joule}}{\text{second}} $

Considering the options provided:

• Kelvin (K): Unit of thermodynamic temperature.
• Watt (W): Unit of power.
• Ampere (A): Unit of electric current.
• Volt (V): Unit of electric potential difference.

Thus, the correct unit for power is the Watt.