Category: Steam and Gas Turbines Objective Questions

Steam and Gas Turbines Multiple Choice Questions on “Fire Resisting Fluids in Steam Turbines”.

1. Fire resistant fluids can be used in __________ pressures.
a) high
b) low
c) both high and low
d) none of the mentioned
Answer: c
Clarification: Fire resistant fluids can be used in high and also low pressure. But mostly fire resistant fluids are used under high pressures as they don’t have any use in the case of low pressures.

2. __________ esters can be used as fire resistant fluids.
a) Phosphate
b) Potassium
c) Sodium
d) None of the mentioned
Answer: a
Clarification: Phosphate esters can be used as fire resistant fluids. As boiling point of phosphate esters are high they can withstand to high temperatures without boiling.

3. Ester mineral blends can also be used as fire resistant fluids.
a) True
b) False
Answer: a
Clarification: Ester mineral blends can also be used as fire resistant fluids. As esters have high boiling points.

4. _______ glycols can also be used as fire resistant fluids.
a) Methylene
b) Ethylene
c) Water
d) None of the mentioned
Answer: c
Clarification: Water glycols can also be used as fire resistant fluids. Water when mixed with glycols their boiling point gets increased and hence these can be used as fire resisting fluids.

5. Fire resistance is _________ proportional to smoothening of the steam.
a) inversly
b) directly
c) fire resistance is not related to steam smootheness
d) none of the mentioned
Answer: b
Clarification: Fire resistance is directly proportional to smoothening of the steam. When there is no fire resistance there will be vigorous combustion taking place which will lead to improper production of steam.

6. Fire resistance of fluids is _______ to the vaporization of the fluid.
a) inversely proportional
b) directly proportional
c) both are no where related
d) None of the mentioned
Answer: a
Clarification: Fire resistance of fluids is proportional to the vaporization of the fluid. If the fluid is highly vaporizable then its fire resistance decreases as fluid gets easily vaporized at low temperatures.

7. __________ is the important feature of the fire resistant fluid.
a) Specific volume
b) Specific heat
c) Viscosity
d) None of the mentioned
Answer: c
Clarification: Viscosity is the important feature of the fire resistant fluid. If the fluid has high viscosity it does not get combusted easily.

8. Fire resistant fluids are selected based on operating ____________
a) temperature
b) pressure
c) temperature & pressure
d) none of the mentioned
Answer: c
Clarification: Fire resistant fluids are selected based on both operating pressure and temperature as pressure is directly proportional to temperature when the volume is constant. Temperature is considered because the fluid that is selected must be able to withstand the working temperature without getting vaporized.

9. ___________ resistance is taken into the consideration while selecting fire resistant fluid.
a) Corrosion
b) Frictional
c) Corrosion & Frictional
d) None of the mentioned
Answer: a
Clarification: Corrosion resistance is taken into the consideration while selecting fire resistant fluid. If the fluid is less corrosion resistant the combustion chambers get corroded easily which leads to break down of the gas turbine.

10. Heat resistant fluids are in _______ color.
a) Black
b) White
c) Colorless
d) None of the mentioned
Answer: b
Clarification: Heat resistant fluids are either red or pink dye color. The quality of the heat resistance offered by the fluid can be determined by the darkness of the color.

Steam and Gas Turbines Multiple Choice Questions on “Classification based on Application, Cycle – 1”.

1. Turbojet is a combination of gas turbine with a propeller engine.
a) True
b) False
Answer: a
Clarification: Turbojet is an air breathing jet engine which was used in aeroplane. Both gas turbine and propeller together is a turbojet.

2. A compressor in the gas turbine is driven by the Turbine.
a) True
b) False
Answer: a
Clarification: In a gas turbine both the turbine and compressor are connected to each other where turbine itself drives the compressor eventually.

3. What is bypass ratio in Turbofan?
a) None of the mentioned
b) (Mass of the air passing through the engine)/(Mass of the air bypassing the engine)
c) (Air entering the engine)/(Air leaving the engine)
d) (Mass of the air bypassing the engine)/(Mass of the air passing through the engine)
Answer: d
Clarification: The term bypass ratio is used in turbofan.In turbofan some of the air enters the engine bypass and rotates the fan while the remaining air rotates the turbine where these two fan and turbine provides the drag force required.Bypass ratio is the ratio of air bypassing the engine to the ratio of air passing through the engine.

4. Turbojet emits ______ engine noise when compared to Turbofan.
a) more
b) less
c) equal
d) none
Answer: a
Clarification: Engine’s noise is directly proportional to the air coming from the engine exhaust.In turbojet more air comes from the engine exhaust which is the reason for more noise.

5. Turboprop engines are used in ________ aircrafts.
a) medium
b) large
c) small
d) none
Answer: c
Clarification: As the air leaving the engine in turboprop is not sufficient to produce required thrust, turboprop engines are used in conditions where less rpms are required.

6. In turboprop engines ____ torque ____ rpm produced from the engine is converted into high rpm low torque.
a) high, low
b) low, high
c) high, high
d) none
Answer: b
Clarification: Turboprop engines generally have low torque and high rpms. In such conditions, a reduction gear is used to convert it into low rpm and high torque so that sufficient drag force can be provided.

7. When turboprop and turbofan operate at same speeds, turboprop consumes ________ fuel.
a) more
b) less
c) equal
d) none
Answer: a
Clarification: Turbofan produces high rpm, low torque but reduction gear is used to convert it into less rpm and high torque to provide required drag force, but turbo fan operates at high rpms, So for turboprop to operate at same speed as of turbofan they require more fuel when compared to turbofan.

8. In turboprop exhaust fan produces ___________
a) more than 25% of the total thrust
b) more than 40% of the total thrust
c) less than 25% of the total thrust
d) less than 10% of the total thrust
Answer: d
Clarification: Due to additional expansion in the turbine system, Energy in the thrust jet is lesser than 10% of the total energy produced by turboprop.

9. Turboprops are not generally operated in high speeds because of ________
a) while speed of the engine increases it looses it efficiency
b) turboprops are not able to produce high speeds
c) turboprops produce high torques
d) none of the mentioned
Answer: a
Clarification: Turboprops cannot be operated at high speeds. Turboprops are operated in between 0.6 and 0.7. When they are operated more than the mentioned speeds they loose their efficiency.

10. A closed cycle gas turbine follows ________
a) Dual Cycle
b) Brayton Cycle
c) Stirling cycle
d) Carnot cycle
Answer: b
Clarification: Closed cycle Gas turbines follow the Brayton cycle.

Steam and Gas Turbines Multiple Choice Questions on “Cooling of Gas Turbine Blades”.

1. Cooling is classified into ________
a) air cooling
b) liquid cooling
c) air & liquid cooling
d) none of the mentioned
Answer: c
Clarification: Cooling is of two types. They are
Air cooling
Liquid cooling.

2. Liquid cooling method has _______
a) high specific heat capacity
b) low specific heat capacity
c) low evaporative cooling
d) none of the mentioned
Answer: a
Clarification: Liquid cooling method has a high specific heat capacity.

3. In liquid cooling leakages are _________
a) increases
b) reduced
c) equal in both air and liquid cooling
d) none of the mentioned
Answer: b
Clarification: In liquid cooling leakages are reduced.

4. Quality of air required for air cooling is ______
a) 1-3 %
b) 2-5 %
c) above 5 %
d) none of the mentioned
Answer: a
Clarification: 1-3% air quality is required for air cooling.

5. By liquid cooling blade temperature can be reduced by ________
a) 300 – 400%
b) 200 – 300%
c) 100 – 500%
d) none of the mentioned
Answer: b
Clarification: Liquid cooling decreases blade temperature by 200-300%.

6. For air cooling,cooling air comes from _________
a) compressor
b) atmosphere
c) condenser
d) none of the mentioned
Answer: a
Clarification: In air cooling, cooling air comes from compressor.

7. In impingement cooling ___________
a) cooling is done by fins
b) by making air with high velocity to hit the blades
c) holes in the blades
d) none of the mentioned
Answer: b
Clarification: In impingement cooling method cooling is done my making air with high velocity to hit the blades.

8. In impingement cooling majority of cooling is done by ________
a) convection
b) conduction
c) radiation
d) none of the mentioned
Answer: a
Clarification: In impingement cooling majority of cooling is done by convection.

9. Impingement cooling is used for lesser loads of heating.
a) True
b) False
Answer: b
Clarification: Impingement cooling is done when lesser loads of cooling is done.

10. In cooling effusion blade surface is made of _______
a) porous material having small orifice
b) fins
c) with larger surface area
d) none of the mentioned
Answer: a
Clarification: In cooling effusion blade surface is made of porous material with small loads so that cooling is more efficiently done.

Steam and Gas Turbines Multiple Choice Questions on “Emergency Governors”.

1. Only some special steam turbines used for special purposes are provided with emergency governors.
a) True
b) False
Answer: b
Clarification: Every steam turbine is provided with an emergency governor.

2. When the speed of the shaft is increased by ________ emergency governors starts.
a) 95%
b) 110%
c) 100%
d) 90%
Answer: b
Clarification: When the speed of the governor is 110% then emergency governors starts working.

3. When balancing of turbine is disturbed _______________
a) Emergency governor starts
b) Governor shuts down
c) Emergency governor starts & Governor shuts down
d) None of the mentioned
Answer: a
Clarification: When balancing of turbines is disturbed, emergency governor starts working.

4. When lubrication system fails _______
a) Turbine shuts down
b) Emergency governor starts
c) Turbine shuts down & Emergency governor starts
d) None of the mentioned
Answer: b
Clarification: When lubrication system fails emergency governor fails.

5. Emergency governor starts working when condenser vacuum is ___________
a) less
b) more
c) medium
d) none of the mentioned
Answer: a
Clarification: When turbine vacuum is reduced emergency governor starts working.

6. When coolant supply is inadequate to condenser ____________
a) Emergency governor starts
b) Condenser instantly shuts down
c) Emergency governor starts & Condenser instantly shuts down
d) None of the mentioned
Answer: a
Clarification: When coolant supply to condenser is inadequate emergency governor starts.

7. Emergency governor starts when _____________
a) Lubrication system fails
b) Turbine balance is disturbed
c) Speed is increased to 110%
d) All of the mentioned
Answer: d
Clarification: Emergency governor starts when
Lubrication system fails
Turbine balancing is disturbed
Speed is increased to 110%.

8. How many governors are required for safe operation of the turbine?
a) 2
b) 1
c) 3
d) 4
Answer: a
Clarification: Two independent governors are required for safe operation. They are
Main governor
Emergency governor.

9. Speed regulation varies from ____________
a) 2.5%-5%
b) 3%-5%
c) 1%-5%
d) 1%-2%
Answer: a
Clarification: Speed regulation varies from 2.5%-5%.

10. Overspeed test for turbine can be done by ____ methods.
a) 1
b) 2
c) 3
d) 4
Answer: b
Clarification: Overspeed test can be done by two methods. They are
DEH dielectric test
Mechanical Test.

Steam and Gas Turbines Multiple Choice Questions on “Centrifugal Compressors Design Calculations”.

1. No of dimensions used in centrifugal compressors are ____________
a) 1
b) 2
c) 3
d) 4
Answer: c
Clarification: Centrifugal compressors use three dimensions. They are
Mass
Length
Time.

2. Flow in a centrifugal compressor is inversely proportional to _______
a) Time
b) Square of time
c) Cube of time
d) None of the mentioned
Answer: a
Clarification: Flow in centrifugal compressor is inversely proportional to the time.

3. Head in centrifugal compressor is __________ to square of the time.
a) directly proportional
b) equal to
c) inversly proportional
d) none of the mentioned
Answer: c
Clarification: Head in centrifugal compressor is inversely proportional to square of the time.

4. Continuity equation can be applied to centrifugal compressor.
a) True
b) False
Answer: a
Clarification: Continuity equation also known as conservation of mass can be applicable to centrifugal compressor.

5. Navier stokes equation is conservation of ____________
a) Mass
b) Momentum
c) Mass & Momentum
d) None of the mentioned
Answer: b
Clarification: Navier stokes equation is conservation of momentum.

6. Centrifugal compressor is an __________
a) irreversible process
b) quasi static process
c) reversible process
d) none of the mentioned
Answer: c
Clarification: Under some circumstances centrifugal compressor is reversible process.

7. In centrifugal compressor flow is ____________
a) radial
b) Perpendicular
c) radial & Perpendicular
d) none of the mentioned
Answer: a
Clarification: In centrifugal compressor flow is radial.

8. In centrifugal compressor centrifugal energy present in the gas is utilized to ___________
a) compress
b) increase temperature
c) radial
d) none of the mentioned
Answer: a
Clarification: In centrifugal compressor centrifugal energy present in the gas is utilized to do work.

9. Centrifugal compressor delivers ____________ flow capacity.
a) high
b) low
c) medium
d) none of the mentioned
Answer: b
Clarification: Centrifugal compressor delivers low flow capacity.

10. Rotating speed of centrifugal compressor is __________ function of diameter to be maintained.
a) inverse
b) direct
c) point
d) none of the mentioned
Answer: a
Clarification: Rotating speed of centrifugal compressor is inverse function of diameter to be maintained.

here is complete set of 1000+ Multiple Choice Questions and Answers

contest