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STEAM TURBINES MULTIPLE CHOICE QUESTIONS (MCQ) WITH ANSWERS

STEAM TURBINES

MULTIPLE CHOICE QUESTIONS

(MCQ) WITH ANSWERS

MCQ on steam turbine increase their

understanding. These also increase level of

clarity. High pressure high temperature is

fed to the convergent divergent nozzles.

The high velocity jet from nozzles strike

the turbine blades. Pressure and velocity

compounded steam turbines are in

existence. Maximum power is produced

using steam turbines. Power weight ratio

is more. Initial cost is more. Vibrations are

less as turbine rotate only in one direction.

Steam engine reciprocates and hence give

more vibrations.

  1. A turbo-generator is

  1. Steam nozzles + Steam turbine

  2. Steam turbine + electric generator

  3. Both (a) & (b)

  4. None

ANS: (b)

  1. A steam turbine converts thermal energy into

  1. Pressure energy & then into kinetic energy

  2. Kinetic energy into mechanical work & then electrical energy

  3. Both (a) & (b)

  4. None

ANS: (c)

  1. A steam turbine confronts with

  1. Vibration + bearing wear

  2. Rotor imbalance & uneven expansion

  3. Both (a) & (b)

  4. None

ANS: (c)

  1. De Laval’s Impulse turbine is

  1. Complex

  2. Simple

  3. Medium complexity

  4. None

ANS: (b)

  1. De Laval’s Impulse turbine is

  1. Expensive

  2. Cheap

  3. Medium cost

  4. None

ANS: (b)

  1. De Laval principle is Impulse action with

  1.  Axial flow

  2.  Radial flow

  3.  Tangential flow

  4. None

ANS: (a)

  1. De Laval turbine is a

  1. Low capacity turbine

  2. High capacity turbine

  3. Both (a) & (b)

  4. None

ANS: (a)

  1. Efficiency of De Laval steam turbine is

  1. High

  2. Low

  3. Medium

  4. None

ANS: (b)

  1. De Laval turbine uses

  1. Convergent nozzles

  2. Divergent nozzles

  3. Convergent-divergent nozzles

  4. None

ANS: (c)

  1. The blades of an impulse steam turbine move

  1. In the direction of steam is flowing

  2. In a perpendicular direction to the steam flow direction

  3. Both (a) & (b)

  4. None

ANS: (a)

  1. The pressure of steam in an impulse turbine is

  1. Variable

  2. Constant

  3. Both (a) & (b)

  4. None

ANS: (b)

  1. De Laval steam turbine is a

  1. Three stage turbine

  2. Two stage turbine

  3. Single stage turbine

  4. None

ANS: (c)

  1. In a single stage impulse turbine, steam nozzles are placed around

  1.  Total circumference of the rotor

  2.  Part of the circumference of the rotor

  3.  One fourth of the circumference of the rotor

  4. None

ANS: (b)

  1. An impulsive force on the steam turbine blades means

  1. A large force for a short time

  2. A small force for a large time

  3. Both (a) & (b)

  4. None

ANS: (a)

  1. Types of steam turbines are

  1. 1

  2. 2

  3. 3

  4. None

ANS: (c)

  1. Types of steam turbines are

  1. Impulse turbine

  2. Reaction turbine

  3. Impulse, Reaction & impulse reaction turbines

  4. None

ANS: (c)

  1. Pressure in a reaction turbine is

  1. Variable

  2. Constant

  3. Both (a) & (b) types

  4. None

ANS: (a)

  1. The Curtis turbine employs

  1. Velocity compounding

  2. Pressure compounding

  3. Both pressure & velocity compounding

  4. None

ANS: (c)

  1. The desirable exit velocity from nozzles in an impulse turbine is

  1. 1500 m/s

  2. 1000 m/s

  3. 500 m/s

  4. None

ANS: (b)

  1. Compounding in steam turbines is done to

  1. Reduce the rotor speed

  2. Increase the rotor speed

  3. Keep constant rotor speed

  4. None

ANS: (a)

  1. In an impulse turbine, both pressure and velocity of steam are

  1. Constant

  2. Variable

  3. Both (a) & (b)

  4. None

ANS: (d)

  1. In a reaction steam turbine, both pressure and velocity are

  1. Variable

  2. Constant

  3. Both (a) & (b)

  4. None

ANS: (a)

  1. Compounding of steam turbines mean it is a

  1. Single stage turbine

  2. Multistage turbine

  3. Single & multistage turbines

  4. None

ANS: (b)

  1. In a velocity compounded steam impulse turbine, magnitude of velocity in fixed nozzles is

  1. Constant

  2. Variable

  3. Both (a) & (b)

  4. None

ANS: (a)

  1. Disadvantage of velocity compounding in an impulse turbine is

  1. High pressure losses

  2. High friction losses

  3. Both (a) & (b)

  4. None

ANS: (b)

  1. Disadvantage of pressure compounding in an impulse turbine is

  1. Nozzles become smaller and smaller

  2. Nozzles become bigger and bulkier

  3. Both (a) & (b)

  4. None

ANS: (b)

  1. Steam turbines are

  1. Condensing

  2. Non-condensing

  3. Both (a) & (b)

  4. None

ANS: (c)

  1. In a condensing steam turbine, pressure at the exit of the turbine is

  1. Above atmospheric

  2. Below atmospheric

  3. Can be above or below atmospheric

  4. None

ANS: (b)

  1. In a non- condensing turbine, the pressure at the exit of the turbine is

  1. Above atmospheric

  2. Below atmospheric

  3. Both (a) & (b)

  4. None

ANS: (a)

  1. Out of condensing and non-condensing turbine, which one is more efficient?

  1. Condensing turbine

  2. Non-condensing turbine

  3. Both are equally efficient

  4. None

ANS: (a)

  1. Pressure staging in steam turbines means number of

  1.  Reaction stages

  2.  Impulse stages

  3.  Velocity compound stages

  4. None

ANS: (b)

  1. Velocity compound staging in steam turbines means number of

  1. Reaction stages

  2. Impulse stages

  3. Velocity compound stages

  4. None

ANS: (c)

  1. Reaction staging in steam turbines means number of

  1. Reaction stages

  2. Impulse stages

  3. Velocity compound stages

  4. None

ANS: (a)

  1. For the same enthalpy drop in a steam turbine, number of reaction stages vs impulse stages is

  1. 1: 2

  2. 2:1

  3. 1:4

  4. None

ANS: (b)

  1. In an Impulse turbines, thrust on bearings

  1. Increases

  2. Decreases

  3. Remains constant

  4. None

ANS: (b)

  1. In a Reaction turbines, thrust on bearings

  1. Increases

  2. Decreases

  3. Remains constant

  4. None

ANS: (a)

  1. Velocity compounding best suits for

  1. Big turbines

  2. Small turbines

  3. Both for small & big turbines

  4. None

ANS: (b)

  1. High velocity in steam turbines

  1. Increase efficiency

  2. Decrease efficiency

  3. Maintains constant efficiency

  4. None

ANS: (b)

  1. High steam velocity in steam turbines

  1. Increases losses

  2. Decrease Losses

  3. No losses

  4. None

ANS: (a)

  1. Power produced by pressure staging vs reaction staging is

  1. 1:1

  2. 1:2

  3. 2:1

  4. None

ANS: (c)

  1. Power produced by velocity compounding in steam turbines vs reaction staging is

  1. 1:1

  2. 2:1

  3. 4:1

  4. None

ANS: (c)

  1. The stage efficiency of reaction stage vs impulse stage is

  1. Lower

  2. Higher

  3. Same

  4. None

ANS: (b)

  1. The turbine efficiency is most effected by the

  1. Outlet blade angle

  2. Inlet blade angle

  3. Heat losses in turbine

  4. None

ANS: (b)

  1. Isentropic efficiency of a steam turbine is the ratio of

  1. Network obtained/ Heat supplied

  2. Network/Isentropic work

  3. Both (a) & (b)

  4. None

ANS: (b)

  1. Stage efficiency of a steam turbine is the ratio of

  1. Work Done per stage/ Energy supplied per stage

  2. Work done per stage / Isentropic energy supplied per stage

  3. Both (a) & (b)

  4. None

ANS: (a)

  1. Blade efficiency in a steam turbine is the ratio of

  1. Work done on the blades Energy supplied to the blade

  2. Change in K.E. on blade/ K.E. supplied to the blade

  3. Both (a) & (b)

  4. None

ANS: (c)

  1. The relation between blade efficiency and nozzle efficiency is

  1. Firstly             η b stage x η nozzle

  2. Secondly        η b stage / η nozzle

  3. Thirdly            η b stage + η nozzle

  4. None

ANS:  (b)

  1. Thermally efficiency of a steam turbine vs reciprocating steam engine at full load is

  1. Higher

  2. Lower

  3. Equal

  4. None

ANS: (a)

  1. Thermally efficiency of a steam turbine vs reciprocating steam engine at part load is

  1. Higher

  2. Lower

  3. Equal

  4. None

ANS: (b)

  1. Power to weight ratio in steam turbines vs steam reciprocating engine is

  1. Less

  2. More

  3. Equal

  4. None

ANS: (b)

  1. Vibrations in a steam turbine vs steam reciprocating engine is

  1. Less

  2. More

  3. Equal

  4. None

ANS: (a)

  1. Mass flow rate of working fluid in steam turbine vs gas turbine is

  1. Less

  2. More

  3. Equal

  4. None

ANS: (a)

https://www.mesubjects.net/wp-admin/post.php?post=6894&action=edit    S turbine & S Engine

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