Consider two hydraulic turbines having identical specific speed and effective head at the inlet. If the speed ratio $$\left( {{{{N_1}} \over {{N_2}}}} \right)$$ of the two turbines is $$2,$$ then the respective power ratio $$\left( {{{{P_1}} \over {{P_2}}}} \right)$$ is _______________________.

Kaplan water turbine is commonly used when the flow through its runner is

In order to have maximum power from a Pelton turbine, the bucket speed must be

A hydraulic turbine develops $$1000$$ $$kW$$ power for a head of $$40$$ $$m.$$ If the head is reduced to $$20$$ $$m,$$ the power developed (in $$kW$$) is