has no effect on

decreases

increases

none of these

improves volumetric efficiency for the given pressure ratio

reduces workdone per kg of air

gives more uniform torque

all of these

Backward curved blades has poor efficiency

Backward curved blades lead to stable performance

Forward curved blades has higher efficiency

Forward curved blades produce lower pressure ratio

30:1

40:1

50:1

60:1

Forward curved blades

Backward curved blades

Radial blades

all of these