Question

In an impulse turbine stage (degree of reaction \(=0\))

• A. Pressure drop occurs only in the rotor
• B. Pressure drop is equally divided between stator and rotor
• C. Pressure drop occurs only in the stator
• D. No pressure drop occurs in the stage

Hint:

For turbine stages, \[ \boxed{ \begin{aligned} R=0 &\rightarrow \text{Impulse Turbine} R=0.5 &\rightarrow \text{Parsons Reaction Turbine} \end{aligned} } \] In an impulse turbine, \[ \boxed{ \Delta P_{\text{Rotor}}=0. } \]

Answer 1

The Correct Option is C

Step 1: Recall the definition of an impulse turbine. For an impulse turbine, \[ \boxed{ R=0, } \] where \(R\) is the degree of reaction. This means there is no pressure drop in the rotor.

Step 2: Determine where the pressure drop occurs. In an impulse stage, \[ \boxed{ \text{the entire pressure drop takes place in the stator (nozzle).} } \] The rotor only changes the direction of the flow and extracts kinetic energy. Therefore, \[ \boxed{\text{Pressure drop occurs only in the stator}} \] is the correct answer. Thus, \[ \boxed{(C)} \] is the correct answer.