# Multiple Choice Questions (MCQ) on Steam nozzles and steam turbines

**Multiple Choice Questions (MCQ) on Steam nozzles and steam turbines**

** **

**A steam nozzle covert **

- heat energy of steam into kinetic energy
- potential energy of steam into kinetic energy
- kinetic energy of steam into mechanical energy
- heat energy of steam into mechanical energy

(Ans:a)

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**The smallest section in nozzle is known as**

- throat
- venturi
- convergent
- divergent

(Ans:a)

**Which of the following is not true for steam nozzles?**

- In convergent nozzle there is divergent after throat
- Convergent-divergent nozzle has higher expansion ratio
- Convergent-divergent nozzle produces steam at higher velocities as compared to a convergent nozzle
- All of the above

(Ans:a)

**Which of the following is true for steam flow through nozzle?**

- The flow is assumed to be adiabatic
- The steam loses its pressure and heat while passing through nozzle
- The work done is equal to the adiabatic heat drop
- All of the above

(Ans:d)

**The maximum velocity of steam at throat is**

- {2(n/n+1) p
_{1}v_{1}}^1/2 - {2(n/n+1) p
_{1}v_{1}}^3/2 - {2(n/2n+1) p
_{1}v_{1}}^1/2 - {2(n/2n+1) p
_{1}v_{1}}^3/2

Where, n=1.135 for saturated steam and 1.3 for superheated steam. p_{1}= initial pressure of steam, v_{1}=initial volume of 1 kg of steam at pressure p_{1}

(Ans:a)

**The correct order in which energy is converted from one form to another, in steam power plant is**

- Kinetic energy – potential energy – mechanical energy – electrical energy
- Kinetic energy – potential energy– electrical energy – mechanical energy
- potential energy – Kinetic energy –mechanical energy – electrical energy
- mechanical energy – potential energy – Kinetic energy –electrical energy

(Ans:c)

**The steam turbine can be governed by the following methods except**

- Throttle governing
- Nozzle governing
- By pass governing
- Reaction governing

(Ans:d)

**In reaction turbine the fixed blade**

- alter the direction of steam
- allow steam to expand to a larger velocity
- functions as same of nozzle
- All of the above

(Ans:d)

**The following are the method for compounding except**

- velocity compounding
- pressure compounding
- volume compounding
- reaction turbine

(Ans:c)

**In velocity compounding, steam is passed through**

- fixed nozzle-moving blades-fixed blades-moving blades
- fixed nozzle-moving blades-fixed nozzles-moving blades
- moving blades-fixed nozzles- fixed blades-moving blades
- fixed blades-moving blades-fixed nozzles- moving blades

(Ans:a)

**In pressure compounding, steam is passed through**

- fixed nozzle-moving blades-fixed blades-moving blades
- fixed nozzle-moving blades-fixed nozzles-moving blades
- moving blades-fixed nozzles- fixed blades-moving blades
- fixed blades-moving blades-fixed nozzles- moving blades

(Ans:b)

**In pressure velocity compounding**

- moving blades are used
- fixed nozzles are used
- fixed blades are used
- All of the above are used

(Ans:d)

**Which of the following is a steam turbine?**

- De laval
- Kaplan
- Francis
- Bulb

(Ans:a)

**Maximum efficiency in impulse steam turbine is**

- 2Cosα
- Cos2α
- Cos(α/2)
- Cos^2α

Where α is nozzle angle

(Ans:d)

**Degree of reaction is given by**

- Heat drop in moving blades
**/**total heat drop in the stage - Heat drop in fixed blades
**/**total heat drop in the stage - Heat drop in moving blades / Heat drop in fixed blades
- total heat drop in the stage / Heat drop in fixed blades

(Ans:a)

**Maximum efficiency in reaction steam turbine is**

- 2Cos^2α/(1+ Cos^2α)
- Cos2α/(1+ Cos^2α)
- Cos(α/2) /(1+ Cos^2α)
- Cosα/(1+ Cos^2α)

Where α is nozzle angle

(Ans:a)