A hydraulic turbine develops 8000 kW when rotating at 100 revolutions per minute. The head on the turbine is 40 m. If the head becomes 10 m, the speed and power developed by turbine are
1
60 rpm, 1100 kW
2
50 rpm, 1000 kW
3
65 rpm, 1700 kW
4
70 rpm, 2100 kW