21. For the same power output, operating charges are minimum in a
- gas turbine plant
- hydro power plant
- thermal plant
- nuclear plant
22. Francis and Kaplan turbines fall under the category of
- impulse turbine
- reaction turbine
- axial flow
- impulse and reaction combined
23. The annual depreciation of a hydro power plant is about
- 5-10 %
- 0.5-1.5 %
- 10-20 %
- 25-30 %
24. Kaplan turbine is
- Inward flow, impulse turbine
- Out ward flow, reaction turbine
- A high head mixed flow turbine
- Low head axial flow turbine
25. Low head plants generally use
- Pelton turbines
- Francis turbines
- Kaplan turbines
- both (a) and (b)
26. The following generating station has the minimum running cost
- Diesel power station
- Nuclear power station
- Hydroelectric power station
- Thermal power station
27. In order to have maximum power from a Pelton turbine, the bucket speed must be
- Equal to the jet speed
- Equal to half the jet speed
- Equal to twice the jet speed
- None of the above
28. The power output from a hydro-electric power plant depends on
- Head, type of dam and discharge
- Type of dam, discharge and type of catchment area
- Type of draft tube, type of turbine and efficiency of the system
- Head, discharge and efficiency of the system
29. A boiler at home is switched on to the AC mains supplying power at 230 V, 50 Hz. The frequency of instantaneous power consumed is
- 0 Hz
- 50 Hz
- 100 Hz
- 150 Hz
30. The maximum continuous power available from a hydroelectric plant under the most adverse hydraulic conditions is known as
- base power
- firm power
- primary power
- secondary power