Category: Steam and Gas Turbines Objective Questions

tricky Steam and Gas Turbines questions and answers on “Classification based on Application, Cycle and Fuel – 2”.

1. This turbine receives steam at high pressure of 600 to 900 psi and discharges it at pressure suitable for supplying to existing low pressure plant. Identify the turbine?
a) Topping Turbine
b) Back-Pressure Turbine
c) Condensing Turbine
d) Extraction Turbine
Answer: a
Clarification: Topping turbine are specially designed turbine for this application in industry.

2. Arjun underwent industrial training in his 2nd year at National Thermal Power Plant. But he was surprised to know that a special turbine is used to meet the electrical energy requirement in the plant itself. Can you identify which turbine did he observe?
a) High Pressure Condensing Turbine
b) House Turbine
c) Gas Turbine
d) Mixed Pressure Turbine
Answer: b
Clarification: Exhaust or extraction steam may be used for feedwater heater.

3. Tanuj and Shyam have a strong discussion over the advantages of Induction-Extraction turbine.
Tanuj: They are employed when a particular manufacturing process require a large quantity of steam at a particular pressure.
Shyam: They are employed when an abundance of waste steam is available at the same pressure. Which one the two you think is correct?
a) Tanuj
b) Shyam
c) Tanuj & Shyam
d) None of the mentioned
Answer: c
Clarification: They are used in both situations.

4. Where in industries do we find back-pressure turbines?
a) At a point in industry where waste steam has to be employed
b) When pressure needs to be applied at rear end
c) When one turbine bolster other
d) There is a requirement of process steam at single pressure
Answer: d
Clarification: These discharge steam into a pressurized piping system to be used for process heating.

5. This turbine is an ingenious method for accomplishing multi velocity staging in a single wheel. Name this turbine?
a) Tangential Turbine
b) Single Stage Impulse Turbine
c) Multi Stage Impulse Turbine
d) None of the mentioned
Answer: a
Clarification: They have reversing chamber equipped with stationary blades which reverses the direction of the steam leaving the moving blades.

6. A marine officer asks you to design a turbine for marine propulsion. Which of the below would be your best choice?
a) Mixed pressure turbine
b) Condensing high pressure regenerative turbine
c) Gas Turbine
d) Tandem-Compound double flow turbine
Answer: b
Clarification: Due to high pressure generated by them.

7. A multipass turbine is a prime mover.
a) True
b) False
Answer: a
Clarification: Prime mover includes every engine that can convert the chemical energy of fuel into useful work.

8. In Europe special types of turbines are used that do not have fixed blades so that pressure drop are necessary in all blade passages. Which turbine is it?
a) Tangential Turbine
b) Axial Flow Turbine
c) Radial Turbine
d) None of the mentioned above
Answer: c
Clarification: They have blades rotating in the opposite direction with two concentric shafts and two generators.

9. You own an industry in which the boiler generates a lot of waste steam which you think could be utilized. Which turbine will you utilize?
a) Mixed Pressure Turbine
b) Back Pressure Turbine
c) Twin-Shaft Gas Turbine
d) Induction-Extraction Turbine
Answer: d
Clarification: They have the capability to admit steam at a given pressure when available.

10. Mac doubts that why do we use House Turbine in National Thermal Power Plants. Can you clear his doubts?
a) The exhaust steam or extraction steam is used for feedwater heating or to supply steam for small turbines serving as auxiliary drives
b) Have huge capacity sufficient enough to run the plant
c) Have minimum losses
d) They can be vertical compounded
Answer: a
Clarification: Their ability to heat feedwater using extraction or exhaust steam.

To practice tricky questions on all areas of Steam and Gas Turbines, here is complete set on 1000+ Multiple Choice Questions and Answers.

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Steam and Gas Turbines Multiple Choice Questions on “Casing and Metallurgical Considerations”.

1. Turbine casing controls _______________
a) working fluid
b) pressure
c) temperature
d) none of the mentioned
Answer: a
Clarification: Turbine casing can also control the working fluid.

2. Turbine casing also contains __________ working fluid.
a) temperature of
b) flow direction of
c) pressure
d) none of the mentioned
Answer: b
Clarification: Turbine casing contains the working fluid and also controls the direction of flow of it.

3. __________ is also used to direct the working fluid.
a) Guide vanes
b) Casing
c) Guide vanes & Casing
d) None of the mentioned
Answer: c
Clarification: Casing can control the working fluid which means it can direct the working fluid.

4. There is a possibility of leakage in between turbine rotor and ________
a) casing
b) valves
c) casing & valves
d) none of the mentioned
Answer: a
Clarification: As casing contains working fluid, there is a problem of leakage in between casing and turbine rotor.

5. In Tandem compound casing a _________ casing are directly coupled together to a generator.
a) single
b) multiple
c) two
d) none of the mentioned
Answer: b
Clarification: In tandem compound casing two or more casings are coupled together to a driven generator.

6. In single casing, Casing is directly coupled to a _____________
a) generator
b) combustor
c) generator & combustor
d) none of the mentioned
Answer: a
Clarification: In single casing, casing is directly coupled to a turbine generator.

7. Cross compounded turbines are used for __________ applications.
a) smaller
b) larger
c) medium
d) none of the mentioned
Answer: b
Clarification: Cross compounded turbines are used for larger applications.

8. Double exhaust rotors have ________ pressure casings.
a) high
b) low
c) medium
d) none of the mentioned
Answer: b
Clarification: Double exhaust rotors use low pressure casings.

9. Two flow rotors use __________ pressure casings.
a) low
b) high
c) medium
d) none of the mentioned
Answer: a
Clarification: Two flow rotors use low pressure casings.

10. In a steam turbine a set of ________ blades are connected to casing.
a) stationary
b) rotating
c) stationary & rotating
d) none of the mentioned
Answer: b
Clarification: In a steam turbine a set of stationary blades are connected to casing.

11. With metallurgical considerations the temperature in Gas turbine blades is reduced by ________
a) 2000 F
b) 3000 F
c) 1000 F
d) none of the mentioned
Answer: a
Clarification: Due to metallurgical consideration the temperature of turbine blades is reduced by 2000F.

12. Due to metallurgical consideration in closed cycle cooling system the upper temperature is limited to _____________
a) 500 C
b) 540 C
c) 200 C
d) none of the mentioned
Answer: b
Clarification: Due to metallurgical consideration in a closed cycle cooling system upper limit is fixed to 540 C.

13. Due to metallurgical consideration _____________ can be limited.
a) pressure
b) volume
c) temperature
d) none of the mentioned
Answer: c
Clarification: Temperature can be limited by metallurgical considerations.

14. For continuous operation in elevated temperature ______________ cooled materials are used for blades.
a) Ceramic
b) Ceramic and liquid
c) Liquid
d) None of the mentioned
Answer: b
Clarification: For continuous operation in elevated temperatures ceramic and liquid cooled materials are used for turbine blades.

15. Metallurgical considerations ________________ the material can bare which is used to manufacture blades.
a) maximum temperature
b) maximum pressure
c) maximum temperature & pressure
d) none of the mentioned
Answer: c
Clarification: Metallurgical consideration define the maximum temperature and pressure the metal can bare which is used to manufacture the blade.

Steam and Gas Turbines Multiple Choice Questions on “Turbine Perfomance and Effect of Throttle Governing”.

1. In small turbines initial cost for throttle governing is ________
a) Low
b) High
c) Same as of Big turbines
d) None of the mentioned
Answer: a
Clarification: In small turbines initial cost of throttle governing is low.

2. In small turbines throttle valve is actuated by ________
a) Pneumatic governor
b) Hydraulic governor
c) Centrifugal governor
d) None of the mentioned
Answer: c
Clarification: In small turbines throttle valve is actuated by centrifugal governor.

3. Turbine shaft and rotating shafts are connected by a gear mechanism.
a) True
b) False
Answer: a
Clarification: Both turbine shaft and rotating shaft are connected by a gear mechanism.

4. Sleeves of the governor rotate ___________
a) perpendicularly
b) parallel
c) axially
d) none of the mentioned
Answer: c
Clarification: Both turbine shaft and rotating shafts are connected by a gear mechanism axially.

5. When the load is decreased the turbine shaft speed is ____________
a) decreased
b) increased
c) remains constant
d) none of the mentioned
Answer: b
Clarification: When the load is decreased the turbine shaft speed is increased.

6. In big turbines ________ is used to increase the lever sensitivity.
a) Servo mechanism
b) Centrifugal governor
c) Gear mechanism
d) None of the mentioned
Answer: a
Clarification: In big turbines servo mechanism is used to increase the lever sensitivity.

7. Small deflections in the lever are magnified by _______
a) mass flow Governor
b) servo mechanism
c) mass flow
d) none of the mentioned
Answer: c
Clarification: Small deflections in the lever are magnified by relay system.

8. When volume of flow is limited produced power _______
a) Limits
b) Varies
c) There is no relation
d) None of the mentioned
Answer: a
Clarification: When volume of flow is limited it limits produced power also.

9. Pressure of the steam is __________ at the entry during throttle governing.
a) increased
b) decreased
c) remained constant
d) none of the mentioned
Answer: b
Clarification: In throttle governing available energy is limited by reducing the pressure of steam at the entry.

10. In throttle governing, flow rate is controlled by steam control valve.
a) True
b) False
Answer: a
Clarification: Partially opened steam controlled valve is used to control flow rate in throttle governing.

tough Steam and Gas Turbines Questions on “Combustion and Thermochemistry”.

1. Combustor is also known as __________
a) flame holder
b) burner
c) flame holder & burner
d) none of the mentioned
Answer: a
Clarification: Combustion takes place in combustor. It is also known as flame holder. Combustor can also be called as burner. Flame holder is used to hold the flame in the combustor.

2. In gas turbine combustion chamber is fed with __________ pressure high temperature gas.
a) low
b) high
c) medium
d) none of the mentioned
Answer:b
Clarification: In gas turbine combustor is fed with high pressure gas. As the pressure is very high as soon as oxygen is supplied in fuel starts burning.

3. When combustor pressure decreases efficiency _________
a) increases
b) decreases
c) remains constant
d) none of the mentioned
Answer: b
Clarification: When combustor pressure decreases its efficiency decreases as it is directly proportional.

4. In an ideal combustor exit temperature must be _________
a) decreasing
b) increasing
c) constant
d) none of the mentioned
Answer: c
Clarification: When exit temperature is not uniform thermal stress develops on the walls of combustor.

5. In air crafts combustors are constrained by size and weight.
a) True
b) False
Answer:a
Clarification: In air craft combustors are constrained by size and weight.

6. Combustors ________ pollutants.
a) increase
b) decrease
c) remains constant
d) none of the mentioned
Answer: b
Clarification: Combustors reduce pollutants. The work of combustor is to assure that fuel is completely burned, when the fuel is completely burned pollutants will be reduced.

7. Swirler is the _____ part in the combustor.
a) first
b) middle
c) last
d) none of the mentioned
Answer: a
Clarification: When air enters combustor it firstly passes through swirler where it induces swirling motion.

8. Nitrogen oxides are released from ________
a) combustors
b) burners
c) combustors & burners
d) none of the mentioned
Answer: c
Clarification: Nitrogen oxide is also a type of pollutant released from combustor.

9. CO pollutant released from combustor is emitted during _______ process.
a) reduction
b) oxidation
c) co is released no where
d) none of the mentioned
Answer: b
Clarification: Carbon monoxide is released during oxidizing process.

10. Nitrogen oxides are produced during combustion zone.
a) True
b) False
Answer: a
Clarification: Nitrogen oxides are produced during combustion zone.

To practice tough questions on all areas of Steam and Gas Turbines, here is complete set of 1000+ Multiple Choice Questions and Answers

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Steam and Gas Turbines Multiple Choice Questions on “Starting and Performance”.

1. In order For turbine to get started air must start flowing ______ to start combustion.
a) outside
b) inside
c) compressing
d) none of the mentioned
Answer: b
Clarification: In a gas turbine in order to start combustion oxygen is required and hence air must start flowing initially.

2. Watt/s is called as a _______
a) joule
b) kilo newton
c) kilo newton/metre
d) none of the mentioned
Answer: a
Clarification: Watt/s is called as a joule.

3. When the amount of energy required is high the life of gas turbine ________
a) not related
b) decreases
c) increases
d) none of the mentioned
Answer: c
Clarification: When the amount of energy required is high the life of gas turbine decreases. Because when amount of power required is high its load increases beyond the limit and hence life decreases.

4. In gas turbines _________ output igniters are used at the starting.
a) low
b) high
c) medium
d) none of the mentioned
Answer: b
Clarification: In gas turbines low output igniters are used when the turbine needs to be run continuously.

5. Electronic igniters can be adjusted as per the required ________
a) output
b) power
c) compressing
d) none of the mentioned
Answer: a
Clarification: Electronic igniters are used as per the required output.

6. When gas turbine is required to operate continuously then power output is ________
a) increased
b) decreased
c) constant
d) none of the mentioned
Answer: b
Clarification: When gas turbine is required to operate continuously the power output is to be reduced as continuous supply of output is needed.

7. When the energy output is __________ igniters life also increases.
a) increased
b) constant
c) decreased
d) none of the mentioned
Answer: c
Clarification: When the igniters life is to be increased then the energy output is decreased. When igniters are used to produce high outputs their life is decreased.

8. Gas turbines has _________ pressure high volume fuel pumps.
a) high
b) low
c) medium
d) none of the mentioned
Answer: b
Clarification: Gas turbines has low pressure and high volume fuel pumps. In gas turbines pressure energy in the working fluid is used to increase volume.

9. In some gas turbines cavitations are _______ by using fuel cooled oil cooler.
a) removed
b) increased
c) cavitations are not caused due to oil cooler
d) none of the mentioned
Answer: a
Clarification: In fuel cooled oil cooler it heats the fuel to high temperature so that the water droplets present in the fuel gets evaporated and hence prevents the cavitation.

10. In gear type fuel pumps bypass action is due to spill valve.
a) True
b) False
Answer: a
Clarification: In gear type fuel pump the bypass action is carried out by spill valve.