Power is the RATE of use, flow, or transfer of energy.
1 watt = 1 joule PER SECOND.
The correct choice is ' <em>a</em> '.
Fundamental quantity : quantities which are independent on other physical quantity .
ex: length,mass,time, current, amount of substance, luminous intensity, thermodynamic temperature,
Derived quantity : quantities which are depend on fundamental quantities.
ex: Area, volume, density, speed, acceleration, force, velocity etc.
