**The ****undershot water wheels are those in ****which – ****the wheel runs entirely by the Impulse of water**

**B****reaking ****jet in an impulse turbine used to ****– to ****bring the runner ****to rest ****in short time **

**A reciprocating pump ****– requires air vessel.**

**A**** Pelton ****wheel is ****– ****tangential ****flow impulse turbine**

**A****n ****impulse turbine used ****for – ****high head of water**

**T****he ****hydraulic efficiency of an impulse turbine is the ****– ratio ****of the work done on the wheel to the energy of the ****jet.**

**The ****mechanical efficiency of an impulse turbine is the ****– ****ratio ****of the actual work available at the turbine to the energy imparted to the wheel**

**The ****hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is one of the jet velocity ****– ****one-half**

**He ****maximum hydraulic efficiency of an impulse turbine ****is – (****1 ****+ ****cos)/2**

**The ****overall efficiency of ****pelton** ** ****wheels lies ****between – ****0.85 to 0.90 **

**D****ouble ****overhung ****pelton**** wheel has ****– two ****runners **

**The width of the ****bucket for a ****Pelton ****wheel is generally the diameter of ****jet – ****5 ****times**

**The ****depth of the bucket for a ****pelton**** wheel is generally the diameter ****of- ****1.2 times**

**Jet ****ratio is defined as the ratio of the ****– ****diameter ****of ****pelton**** wheel to the diameter of jet**

** ****The ****number of packets on the Periphery of a ****pelton**** wheel is given ****by- ****D/2d+****15**

**In ****an inward flow reaction ****turbine – ****the water enters the wheel at the outer Periphery and then flow towards the ****centre**** of the ****wheel**

** Overall ****efficiency of a reaction turbine is the ratio of ****– power ****produced by the turbine to the energy actually supplied by the turbine**

**The ****Runaway speed of hydraulic turbine is the speed ****– ****at ****which the turbine will run freely without load **

**The ****power developed by turbine ****is – ****directly proportional ****to H**

**the unit power developed by turbine ****is – P/****H**

**The ****speed of turbine runner is directly proportional ****to – ****H**

**The ****unit of speed of the turbine runner ****is – ****N/H**

**The ****unit discharge through the turbine ****is – ****Q/H**

**The ****specific speed of turbine is given by the ****equation – ****NP **

**Which ****of the following turbine is preferred 40 to 25 m head of water ****– ****Kaplan turbine **

**Which ****of the following turbine is preferred for a specific speed of 60 to 300 ****r.p.m**** – ****Francis turbine**

**For ****450 ****m head of ****water shall be used ****– ****P****elton wheel**

** A Pelton wheel working under a constant head and discharge has maximum efficiency when the speed ratio is ****– ****0.46**

**the ****Cavitation ****in a hydraulic machine is mainly due ****to – ****low ****pressure**

**multi-stage centrifugal pumps are used to produce – ****high ****heads**

**slip of reciprocating pump is defined ****as – ****the difference of theoretical discharge and the actual discharge**

**in a reciprocating pump air vessels are used ****to – ****reduce acceleration head**

**discharge of centrifugal pump ****is – ****directly proportional to ****N**

**Delivery head of centrifugal pump is directly proportional to N **

**For centrifugal pump ****pump**** impeller the maximum value of the vane exit angle is 20 to 25 degree**

**which of the following is successfully used for lifting water from deep wells – ****air lift pump**

** which of the following is successfully used for lifting water to the turbine – ****Jet pumps**

**Centrifugal pumps operating in series will result in – ****higher head**