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Driving force in an impulse–reaction turbine For an impulse–reaction turbine stage, identify the nature of the driving force acting on the moving blades. Choose the correct option.

Difficulty: Easy

An impulsive force only
A reaction force only
Partly impulsive and partly reaction
None of the above

Correct Answer: Partly impulsive and partly reaction

Explanation:

Concept
In an impulse–reaction stage, part of the pressure drop occurs in the fixed nozzles (impulse component) and part within the moving blades (reaction component). The resulting torque arises from both the change in jet momentum (impulse) and from pressure forces across the rotor passages (reaction).

Final Answer
Partly impulsive and partly reaction

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