Category: Steam and Gas Turbines Objective Questions

Steam and Gas Turbines Multiple Choice Questions on “Wet and Supersaturated Steam”.

1. Mixture of steam and liquid water is called as _________
a) dry steam
b) wet steam
c) saturated steam
d) none of the mentioned
Answer: b
Clarification: Mixture of steam and liquid water is called as wet steam. Where as dry steam is boiled steam and sometimes dry steam is also called as saturated steam.

2. Supersaturated steam is also called as _________
a) saturated steam
b) single phase mix
c) two phase mix
d) none of the mentioned
Answer: c
Clarification: In supersaturated steam there is a mixture of two phases gaseous and liquid, so it is called a two phase mix.

3. If heat is added to the wet steam temperature _________
a) raises immediately
b) decreases immediately
c) raises after sometime
d) none of the mentioned
Answer: c
Clarification: When heat is added to the steam immediately the liquid particles try to evaporate and form saturated steam only after that the temperature starts rising.

4. After steam bubbles break the water surface, they carry water droplets this is called as ________
a) entrainment
b) capillarity
c) reverse capillarity
d) none of the mentioned
Answer: a
Clarification: When steam bubbles break water surface they carry some water droplets. This process is called as entrainment.

5. Entrainment happens at __________
a) liquid surface having contact with atmosphere
b) outlet of the boiler
c) inlet of the boiler
d) none of the mentioned
Answer: b
Clarification: Entrainment happens at the outlet of the boiler.

6. Hydraulic water hammer is caused by _______
a) wet steam
b) dry steam
c) pressurized water
d) none of the mentioned
Answer: a
Clarification: Hydraulic water hammer is caused by wet steam.

7. Hydraulic water hammer is caused due to ______
a) humidity in pipelines
b) accumulation of condensate
c) humidity in pipelines & accumulation of condensate
d) none of the mentioned
Answer: c
Clarification: Hydraulic water hammer is caused due to humidity on pipelines or accumulation of condensate.

8. Resistance of water dominating the steam is called as _______
a) hydraulic water hammer
b) erosion
c) contamination
d) none of the mentioned
Answer: b
Clarification: Resistance of water hammer dominating steam is called erosion.

9. When steam is transported dryness fraction _________
a) increases
b) decreases
c) remains constant
d) none of the mentioned
Answer: b
Clarification: When steam travels in pipeline its dryness fraction increases.

10. Wet steams causes corrosion.
a) True
b) False
Answer: a
Clarification: Wet steam may cause
corrosion
erosion
hydraulic water hammer in pipelines
destroy turbine blades etc.

Steam and Gas Turbines Multiple Choice Questions on “Losses in Impulse Blade Passages”.

1. ____________ is developed when working fluid is passed through blade passage.
a) Internal heat loss
b) External heat loss
c) Heat loss
d) None of the mentioned
Answer: a
Clarification: When working fluid is passing through blade passage, due to friction internal heat loss occurs.

2. Kinetic energy of working fluid is _________ kinetic energy of case lossless flow.
a) Equal to
b) Lesser than
c) Greater than
d) Depends on the situation
Answer: c
Clarification: Kinetic energy of the case lossless flow is lesser than the kinetic energy of working fluid.

3. Ratio of actual velocity to velocity of case lossless flow is called as _______
a) Velocity coefficient
b) Velocity gradient
c) No specific ratio
d) None of the mentioned
Answer: a
Clarification: Velocity coefficient is the ratio of actual velocity to velocity of case lossless flow.

4. Difference between actual enthalpy of working fluid to case enthalpy of isoentropic flow is called as _______
a) Case lossless flow
b) Entropy change
c) Losses
d) None of the mentioned
Answer: c
Clarification: Losses are the enthalpy differences between working fluid and casses of isoentropic flow.

5. The losses occurred due to enthalpy changes is caused due to _________
a) Pressure difference
b) Friction
c) Temperature difference
d) None of the mentioned
Answer: b
Clarification: Friction causes the enthalpy change.

6. Velocity coefficient is applicable for __________
a) Parallel flow passage
b) Counter flow passage
c) All types of flow passages
d) None of the mentioned
Answer: c
Clarification: Velocity coefficient is applicable for all types of flow passages.

7. Velocity coefficient can be applied for ___________ flow passage.
a) convergent
b) divergent
c) depends on
d) none of the mentioned
Answer: a
Clarification: Velocity coefficient can be applied for any flow passage.

8. Velocity coefficient can be applied for __________ blade passage.
a) none
b) impulse
c) reaction
d) any
Answer: d
Clarification: Velocity coefficient can be applied for any flow passage.

9. Blade profile losses for a diffuser blade depends on ____________
a) Enthalpy
b) Entropy
c) Kinetic energy
d) None of the mentioned
Answer: c
Clarification: Blade profile losses for a diffuser blade is related to the kinetic energy.

10. Blade profile losses are ____________ losses of the stages at turbomachine.
a) Greater
b) Smaller
c) Equal
d) None of the mentioned
Answer: b
Clarification: Losses at the stages of turbomachines are greater than blade profile losses.

Steam and Gas Turbines Multiple Choice Questions on “Parsons Number and Quality Factor”.

1. Vapor quality is the ___________ stored in the steam.
a) mass factor
b) pressure factor
c) temperature factor
d) none of the mentioned
Answer: a
Clarification: Vapor quality is used to know the amount of mass stored in steam.

2. Saturated liquid’s vapor quality is ________
a) 100%
b) 50%
c) 0%
d) 60%
Answer: c
Clarification: In a saturated liquid no vapor is present and hence vapor quality of saturated liquid is 0%.

3. Vapor quality of saturated steam is ________
a) 100%
b) 50%
c) 0%
d) 60%
Answer: a
Clarification: In a saturated vapor the vapor quality is 100%.

4. Vapor quality is an ___________
a) extensive property
b) intensive property
c) extensive & intensive property
d) none of the mentioned
Answer: b
Clarification: Vapor quality is an intensive property.

5. Vapor quality cannot be used to distinguish thermodynamic state of the fluid from others.
a) True
b) False
Answer: b
Clarification: As vapor quality is an intensive property it can be used with the other intensive properties to distinguish the thermodynamic stage.

6. Vapor quality can be calculated by ____________ the total mass of the vapour present with mass of the fluid.
a) dividing
b) multiplying
c) adding
d) none of the mentioned
Answer: a
Clarification: Vapor quality is obtained by dividing mass of the vapor present in fluid with the total mass of the fluid.

7. ________ quality steam contains low moisture percentage.
a) high
b) medium
c) low
d) none of the mentioned
Answer: c
Clarification: Low quality steam has high moisture percentage.

8. ________ quality steam causes corrosion.
a) high
b) low
c) medium
d) none of the mentioned
Answer: b
Clarification: As low quality steam contains high moisture percentage, it corrodes easily.

9. In steam whistles steam quality determines the ___________
a) velocity of sound
b) pressure
c) temperature
d) none of the mentioned
Answer: a
Clarification: Velocity of sound in steam whistles depends on steam quality as steam inertia depends on steam quality.

10. Specific volume of steam is ___________ to dryness faction at given temperature.
a) not related
b) indirectly proportional
c) directly proportional
d) none of the mentioned
Answer: c
Clarification: At given temperature specific volume of steam increases with an increase in dryness faction.

Steam and Gas Turbines Multiple Choice Questions on “Mechanics of Combustion”.

1. In combustion the _______________ is released from breaking the chemical bonds.
a) chemical energy
b) heat energy
c) kinetic energy
d) none of the mentioned
Answer: a
Clarification: When required heat energy is supplied chemical bonds break and release energy.

2. In combustion mechanism chain branching is represented by ______
a) g
b) f
c) a
d) t
Answer: b
Clarification: In combustion mechanism chain branching is represented by f.

3. In combustion mechanism chain termination is represented by ________
a) t
b) b
c) g
d) f
Answer: c
Clarification: In combustion mechanism chain termination is represented by g.

4. If g is _______ than f then termination exceeds branching.
a) greater
b) lesser
c) equal
d) none of the mentioned
Answer:a
Clarification: If g is greater than f then termination exceeds branching.

5. If f is ___________ than g then branching exceeds termination.
a) equal
b) lesser
c) greater
d) none of the mentioned
Answer: c
Clarification: If f is greater than g then branching exceeds termination.

6. Low oxygen pressures assures g _________ f.
a) lesser than
b) greater
c) equal to
d) none of the mentioned
Answer: b
Clarification: Low oxygen pressures assure g greater than f.

7. High oxygen pressure assure g ________ f.
a) lesser than
b) greater than
c) equal to
d) none of the mentioned
Answer: a
Clarification: High oxygen pressure assure g less than f.

8. Rate of combustion depends upon radial concentration.
a) True
b) False
Answer: a
Clarification: Rate of combustion depends upon radial concentration.

9. Hydrogen oxygen reaction depends upon ________
a) pressure concentration
b) temperature gradient
c) temperature
d) none of the mentioned
Answer: a
Clarification: Hydrogen oxygen reaction depends on pressure.

10. Hydrocarbon combustion is of __________
a) two
b) one
c) three
d) none of the mentioned
Answer: a
Clarification: Hydrocarbon combustion is of two types. They are hydro carbon breaking and oxidizing.

Steam and Gas Turbines Multiple Choice Questions on “Usage of Cryogenics in Gas Turbines”.

1. In cryogenic rocket engines use oxidizer as fuel.
a) True
b) False
Answer: a
Clarification: In cryogenic rocket engines use oxidizer as fuel.

2. Cryogenic fuels are stored under _______ temperatures.
a) high
b) low
c) medium
d) none of the mentioned
Answer: b
Clarification: Cryogenic rocket fuels are stored under low temperatures. Cryogenics works under minus degree Celsius and hence they are stored in low temperatures.

3. Rocket engines require _______ mass flow rate.
a) high
b) low
c) medium
d) none of the mentioned
Answer: a
Clarification: Rocket engines require high mass flow rate. Rocket engines requires high thrust and for producing high thrust high mass flow rate is required.

4. Rocket fuels has ________ molecular weight.
a) medium
b) high
c) low
d) none of the mentioned
Answer: c
Clarification: Rocket fuels has low molecular weight.

5. Cryogenic fuels are in _________ state at room temperature and pressure.
a) gaseous
b) liquid
c) solid
d) none of the mentioned
Answer: a
Clarification: Cryogenic fuels are in a gaseous state at room temperature and pressure. Cryogenics work under low temperatures and when temperature is changed to room temperature then phase transfer takes place.

6. Cryogenic rocket engines are also called as hybrid rocket engines.
a) True
b) False
Answer: a
Clarification: Cryogenic rocket engines are also called as hybrid rocket engines.

7. Hybrid rocket engines are also called as ________ propellant rocket engines.
a) solid
b) liquid
c) solid & liquid
d) none of the mentioned
Answer: b
Clarification: Hybrid rocket engines are also called as liquid propellant rocket engines. Because fuels used in hybrid engines are in liquid state.

8. ____________ is used as cryogenic fuel.
a) Liquid oxygen
b) Liquid hydrogen
c) Combination of liquid oxygen and liquid hydrogen
d) None of the mentioned
Answer: a
Clarification: Combination of both liquid oxygen and liquid hydrogen are used as cryogenic fuel. Mixture of this liquid oxygen and liquid hydrogen results in low temperature which is a main property of cryogenic fuels.

9. Liquid hydrogen and oxygen mixture produces thrust upto ________
a) 5 Km/s
b) 4 Km/s
c) 4.5 Km/s
d) 5.5 Km/s
Answer: c
Clarification: Liquid hydrogen and oxygen mixture produces thrust upto 4.5 Km/s. Cryogenic fuels produce high thrust force.

10. _________ initiators are used in cryogenic rocket engines.
a) Pyrotechnic
b) Centrifugal
c) Pyrotechnic & Centrifugal
d) None of the mentioned
Answer: a
Clarification: Pyrotechnic initiators are used in cryogenic rocket engines.

Steam Turbine Interview Questions and Answers on “Heat and Steam Rate”.

1. Heat rate defines how much energy is to be expanded for obtaining a unit of useful work.
a) True
b) False

Answer: a
Clarification: Heat rate means the amount of energy that must be expanded for obtaining an unit of useful work.

2. What is heat rate in turbine?
a) Heat required for unit of power generated in specific conditions and specific fuel burning
b) Amount of heat required to expand turbine blades
c) Amount of heat required to increase pressure of steam
d) None of the mentioned

Answer: a
Clarification: Heat rate in turbines is defined as heat required to generate unit power in turbine at specific fuel being burned at specific conditions.

3. For calculating heat rate in steam turbines enthalpy is calculated.
a) False
b) True

Answer: b
Clarification: Heat rate can be calculated by using enthalpy method.

4. Steam turbine governing can be defined as __________
a) increasing the steam speed
b) adjusting the governors for particular speeds
c) controlling the flow rate of steam
d) none of the mentioned

Answer: c
Clarification: Governors are used to control the fuel needed to the load and they are no way related to the steam turbine governing. Steam turbine governing is controlling the flow rate of steam.

5. Why is steam turbine governing used?
a) To increase the steam speed
b) To maintain steam speed constant
c) To decrease the steam speed
d) None of the mentioned

Answer: b
Clarification: Flow rate if steam is controlled to maintain the constant speed.

6. In nozzle governing the flow rate is controlled by ____________
a) opening and closing the valves at nozzle
b) adding more number of nozzles
c) increasing nozzle efficiency
d) none of the mentioned

Answer: a
Clarification: Opening and closing of valves at nozzle is called nozzle governing.

7. During overload of turbines __________ are used.
a) throttle governing
b) nozzle valves
c) bypass governing
d) none of the mentioned

Answer: c
Clarification: During overload conditions fresh steam is added into later stages called as bypass governing.

8. When is emergency governing used?
a) Speed of shaft increased above 110%
b) When turbine is shut down due to overload
c) When Low steam is entering
d) None of the mentioned

Answer: a
Clarification: When speed of shaft is increased to 110% then emergency governing is used to control the speed.

9. When balancing of the turbine is disturbed ___________ is used.
a) Potter governor
b) Centrifugal governor
c) Emergency governor
d) None of the mentioned

Answer: c
Clarification: Emergency governor is also used when balancing of the turbine is disturbed.

10. When lubrication is failed _____________ is used.
a) Centrifugal governor
b) Emergency governor
c) Potter governor
d) None of the mentioned

Answer: b
Clarification: Emergency governor is used in all emergency situations like when the lubrication system is failed, when speed is increased when balancing is disturbed etc.

Steam Turbines for Interviews,