A micro-hydroelectric generator installed in a mountain stream has a power rating which varies from 0.4 kW0.4\text{ kW}0.4 kW to 3.0 kW3.0\text{ kW}3.0 kW.
The generator has an internal electrical resistance of 25 Ω25\ \Omega25 Ω. During a period of high water flow, it operates with a current of 8.0 A8.0\text{ A}8.0 A.
Calculate the power output of the generator during this period in kilowatts (kW\text{kW}kW).
Explain why the manufacturer states a range of power ratings rather than a single value.