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Multiple choice question for engineering

Set 1

1. Which of the following is a water tube boiler?
a) Lancashire boiler
b) Cochran boiler
c) Babcock & Wilcox boiler
d) Locomotive boiler

View Answer

Answer: c [Reason:] The Cochran Boiler is a type of water tube boiler.

2. The number of fire tubes in a Cochran boiler are
a) 75
b) 165
c) 225
d) 175

View Answer

Answer: b [Reason:] The number of fire tubes in a Cochran boiler is 165.

3. The chimney draught varies with?
a) climatic conditions
b) temperature of furnace gases
c) height of chimney
d) all of the mentioned

View Answer

Answer: d [Reason:] The chimney draught varies with climatic conditions, temperature of furnace gases, height of chimney, etc.

4. The diagram factor is the ratio of?
a) area of actual indicator diagram to the area of theoretical indicator diagram
b) actual work done per stroke to the theoretical work done per stroke
c) actual mean effective pressure to the theoretical mean effective pressure
d) any of the above mentioned

View Answer

Answer: d [Reason:] The ratio of any of the mentioned factors is called the Diagram factor.

5. The diameter of a cylindrical shell of a Scotch marine boiler varies from
a) 3.5 to 4.5m
b) 1.5 to 2m
c) 2.5 to 3.5m
d) none of the mentioned

View Answer

Answer: c [Reason:] The diameter of a cylindrical shell of a Scotch marine boiler varies from 2.5 to 3.5m.

6. A closed vessel made of steel & used for the generation of steam is called a
a) steam condenser
b) steam boiler
c) steam injector
d) steam turbine

View Answer

Answer: b [Reason:] A closed vessel made of steel & used for the generation of steam is called a steam boiler.

7. Lancashire boiler has _____ internal flue tubes
a) 1
b) 3
c) 2
d) 4

View Answer

Answer: c [Reason:] Lancashire boiler has 2 internal flue tubes.

8. Locomotive boiler is a
a) single tube, vertical, externally fired & stationary boiler
b) single tube, horizontal, internally fired& stationary boiler
c) multitubular, horizontal, externally fired & stationary boiler
d) multitubular, horizontal, internally fired & mobile boiler

View Answer

Answer: d [Reason:] Locomotive boiler is a multitubular, horizontal, internally fired & mobile boiler.

9. Cut-off ratio is the ratio of?
a) cut-off volume to clearance volume
b) clearance volume to cut-off volume
c) volume at cut-off to swept volume
d) swept volume to volume at cut-off

View Answer

Answer: c [Reason:] Cut-off ratio is the ratio of volume at cut-off to swept volume.

10. The equivalent evaporation is defined as?
a) the ratio of heat actually used in producing the steam to the heat liberated in the furnace
b) the amount of water evaporated or steam produced in kg of fuel burnt
c) the amount of water evaporated from and at 100 degree C into dry & saturated steam
d) none of the mentioned

View Answer

Answer: c [Reason:] The equivalent evaporation is defined as the amount of water evaporated from and at 100 degree C into dry & saturated steam.

11. The theoretical indicator diagram of a simple steam engine is based upon the assumption that
a) there is no pressure drop due to condensation
b) steam is admitted at boiler pressure & exhausted at condenser pressure
c) the expansion of the steam is hyperbolic
d) all of the mentioned

View Answer

Answer: d [Reason:] The theoretical indicator diagram of a simple steam engine is based upon the assumption that there is no pressure drop due to condensation, the steam is admitted at boiler pressure & exhausted at condenser pressure, the expansion of the steam is hyperbolic.

12. The actual power supplied by the engine crankshaft is called?
a) indicated power
b) frictional power
c) brake power
d) none of the mentioned

View Answer

Answer: c [Reason:] The actual power supplied by the engine crankshaft is called Brake Power.

13. When steam after doing work in the cylinder passes into a condenser, the engine is said to be a
a) slow speed engine
b) vertical steam engine
c) condensing steam engine
d) no-condensing steam engine

View Answer

Answer: c [Reason:] When steam after doing work in the cylinder passes into a condenser, the engine is said to be a condensing steam engine.

14. The missing quantity per stroke is equal to?
a) cylinder feed + indicated mass of steam
b) cylinder feed + indicated mass of steam
c) mass of cushion steam + indicated mass of steam
d) mass of cushion steam + cylinder feed

View Answer

Answer: b [Reason:] The missing quantity per stroke is equal to cylinder feed + indicated mass of steam.

15. An economiser is installed in a boiler primarily to
a) increase steam pressure
b) reduce fuel consumption
c) superheat the steam
d) all of the mentioned

View Answer

Answer: b [Reason:] An economiser is installed in a boiler primarily to reduce fuel consumption.

Set 2

1. Production of producer gas from coke requires _____________ moles of nitrogen.
a) 3.76
b) 4.51
c) 2.23
d) 3.49

View Answer

Answer: a

2. Which of the following mode is not used to liquefy coal?
a) hydrogenation
b) catalytic conversion
c) hydro pyrolysis
d) coal gasification

View Answer

Answer: d [Reason:] In coal gasification, coal is gasified in a situ and the gas is conveyed to the surface. The other processes are methods of coal liquefaction.

3. What are the first products in Fischer-Tropsch process?
a) CO+H2
b) CO2 +H2
c) Coke + H2O
d) Coke

View Answer

Answer: a [Reason:] The first products in Fischer-Tropsch process are carbon monoxide and hydrogen.

4. ____________ prohibits the use of alcohols directly in petrol engines.
a) high cost and availability
b) low octane number
c) low flash point
d) low calorific value

View Answer

Answer: a [Reason:] High cost is the reason for no use of alcohols in petrol engines.

5. Which of these is not a form of bioconversion route?
a) direct combustion
b) fermentation
c) thermochemical conversion
d) biochemical conversion

View Answer

Answer: b [Reason:] Fermentation is breakdown of complex molecules in organic compounds. It is a type of biochemical conversion.

6.Which of these is a product of pyrolysis process in dry thermochemical conversion?
a) methane
b) methanol
c) ammonia
d) pyrolytic oils

View Answer

Answer: d [Reason:] Pyrolytic oils, gas and char are the products of pyrolysis process.

7. Which of these is an important measure of performance in for a power plant?
a) NPHR
b) AP
c) NTO
d) HHV

View Answer

Answer: a [Reason:] NPHR- net plant heat rate is a most important measure of performance for power plant.AP-auxillary power NTO-net turbine output NTHR-net turbine heat rate.

8. The overall efficiency of a power plant is given by
a) 3600/NTO
b) 3600/AP
c) 3600/HHV
d) 3600/NPHR

View Answer

Answer: d [Reason:] The overall efficiency of a power plant is given by ɳ=3600/NPHR.

Set 3

1. If p and q are the efficiencies of a Brayton & Rankine cycles respectively in a Brayton-Rankine combined plant, the efficiency n of a combined plant is?
a) n = p/q
b) n = p+q-pq
c) n = pq
d) n = (1 – pq)

View Answer

Answer: b [Reason:] The efficiency of a Brayton-Rankine combined plant when p and q are the efficiencies of a Brayton & Rankine cycles respectively is given as, n = p + q – pq.

2. Which of these is a working fluid in the topping plant of a Brayton-Rankine combined plant?
a) Hydrogen
b) Helium
c) Nitrogen
d) All of the mentioned

View Answer

Answer: b [Reason:] The low molecular mass of Helium makes it the most suitable working fluid in the topping plant.

3. Which of these is a working fluid in the bottoming plant of a Brayton-Rankine combined plant?
a) Mercury
b) Steam
c) Water
d) Air

View Answer

Answer: c [Reason:] Water is the bottoming fluid due to its high specific heat capacity.

4. What would be the temperature of the gas in the combustion chamber?
a) 500 °C
b) 1600 °C
c) 1200 °C
d) 650 °C

View Answer

Answer: b [Reason:] The gas in the combustion chamber is at a temperature of 1600 °C.

5. The efficiency of the open cycle gas plant is quite low. Why?
a) Gas gets cooled before reaching the turbine wheels
b) A lot of mechanical energy is used up by the compressor
c) Due to the presence of regenerator and absence of air pre heater
d) Both (a) and (b)

View Answer

Answer: d [Reason:] The efficiency of the open cycle gas plant is quite low. This is because of mainly two reasons, Gas gets cooled before reaching the turbine wheels and a lot of mechanical energy is used up by the turbine wheels.

6. To improve the efficiency of the gas turbines, which among these are used?
a) Regenerator
b) Inter cooling
c) Reheating
d) All of the mentioned

View Answer

Answer: d [Reason:] All of the methods- Reheating, Regeneration and Intercooling are used to improve the efficiency of gas turbines.

7. What is regeneration?
a) Removal of heat from compressed air between stages of compression
b) Transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber
c) To increase the temperature of partially expanded gases by burning more fuel
d) Both (b) & (c)

View Answer

Answer: b [Reason:] Transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber is called the process of Regeneration.

8. What is meant by inter cooling?
a) Removal of heat from compressed air between stages of compression
b) Transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber
c) To increase the temperature of partially expanded gases by burning more fuel
d) None of the mentioned

View Answer

Answer: a [Reason:] Removal of heat from compressed air between various stages of compression is called Inter cooling.

9. Which material is used for the manufacture of the turbine blades?
a) Stainless steel
b) Carbon steel
c) High nickel alloy
d) High alloy steel

View Answer

Answer: c [Reason:] High nickel alloy is the most sufficient material for the manufacture of Turbine Blades.

Set 4

1. In turbines, the fluid undergoes a continuous steady flow process and the speed of flow is
a) very high
b) high
c) low
d) very low

View Answer

Answer: a [Reason:] In turbines, the fluid undergoes a continuous steady flow process and the speed of flow is very high.

2. Steam turbines may be classified according to
a) number of stages
b) direction of steam flow
c) mode of steam action
d) all of the mentioned

View Answer

Answer: d [Reason:] The steam turbines are classed under various types based on number of stages, direction of steam flow, mode of steam action, etc.

3. A steam nozzle converts
a) heat energy of steam into kinetic energy
b) kinetic energy of steam into heat energy
c) potential energy into heat energy
d) none of the mentioned

View Answer

Answer: a [Reason:] A steam nozzle converts heat energy of steam into kinetic energy.

4. In a velocity compounded impulse turbine, when steam flows through the second row of moving blades,
a) velocity decreases
b) velocity increases
c) pressure decreases
d) pressure increases

View Answer

Answer: a [Reason:] In a velocity compounded impulse turbine, when steam flows through the second row of moving blades, the velocity decreases.

5. In a reaction turbine when the degree of reaction is zero, then there is
a) no heat drop in moving blades
b) maximum heat drop in fixed blades
c) no heat drop in fixed blades
d) maximum heat drop in moving blades

View Answer

Answer: a [Reason:] In a reaction turbine when the degree of reaction is zero, then there isn’t any heat drop in moving blades.

6. The process of draining steam from the turbine, at certain points during its expansion and using this steam for heating the feed water in feed water heaters and then supplying it to the boiler is known as
a) regenerative heating
b) reheating of steam
c) bleeding
d) none of the mentioned

View Answer

Answer: c [Reason:] The process of draining steam from the turbine, at certain points during its expansion and using this steam for heating the feed water in feed water heaters and then supplying it to the boiler is known as Bleeding.

7. Turbo alternators run at speeds
a) constant speed of 3000 rpm
b) constant speed of 1000 rpm
c) variable speed of 1000 rpm
d) none of the mentioned

View Answer

Answer: c [Reason:] The turbo alternators run at speeds varying in 1000 rpm.

8. In an impulse reaction turbine, the pressure drops gradually and continuously over
a) moving blades
b) fixed blades
c) both moving & fixed blades
d) none of the mentioned

View Answer

Answer: c [Reason:] The pressure drops gradually & continuously over both moving & fixed blades in an impulse turbine.

9. A steam turbine with no nozzle is?
a) Reaction Turbine
b) Impulse Turbine
c) both of the mentioned
d) none of the mentioned

View Answer

Answer: a [Reason:] Reaction turbine is basically a steam turbine without any nozzle.

10. The pipes carrying steam are made up of?
a) Steel
b) Copper
c) Aluminium
d) Iron

View Answer

Answer: a [Reason:] The pipes carrying steam in a steam turbine are made up of Steel.

Set 5

1. The steam leaves the nozzle at a
a) low pressure and a high velocity
b) high pressure and a high velocity
c) high pressure and a low velocity
d) low pressure and a low velocity

View Answer

Answer: a [Reason:] The steam leaves the nozzle at a low pressure & a high velocity as the action of steam is best suited for turbine operations under these conditions.

2. When the back pressure of a nozzle is below the designed value of pressure at exit of nozzle, the nozzle is said to be
a) overdamping
b) underdamping
c) chocked
d) none of the mentioned

View Answer

Answer: b [Reason:] When the back pressure of a nozzle is below the designed value of pressure at exit of nozzle, the nozzle is said to be underdamping.

3. De-Laval turbine is a
a) multi rotor impulse turbine
b) impulse reaction turbine
c) single rotor impulse turbine
d) none of the mentioned

View Answer

Answer: c [Reason:] A De-Laval turbine is a single rotor impulse turbine.

4. The supersaturated flow of steam through a nozzle as compared to a stable flow, the available heat drop
a) increases
b) decreases
c) is unpredictable
d) remains same

View Answer

Answer: b [Reason:] The supersaturated flow of steam through a nozzle as compared to a stable flow, the available heat drop decreases.

5. A turbine is said to have an axial discharge when the steam leaves the blade tip at __________ to the direction of the blade motion
a) 90°
b) 60°
c) 270°
d) 180°

View Answer

Answer: b [Reason:] A turbine is said to have an axial discharge when the steam leaves the blade tip at 60° to the direction of the blade motion.

6. The Parsons’ reaction turbine has
a) only moving blades
b) only fixed blades
c) fixed and moving blades of different shape
d) identical fixed and moving blades

View Answer

Answer: d [Reason:] The Parsons’ reaction turbine has identical fixed & moving blades.

7. The critical pressure ratio for initially wet steam is
a) 0.582
b) 0.546
c) 0.577
d) 0.601

View Answer

Answer: a [Reason:] The critical pressure ratio for initially wet steam is 0.582.

8. The ratio of the useful heat drop to the isentropic heat drop is called
a) condenser efficiency
b) nozzle efficiency
c) vacuum efficiency
d) boiler efficiency

View Answer

Answer: b [Reason:] The ratio of the useful heat drop to the isentropic heat drop is called nozzle efficiency.

9. Rateau turbine is
a) pressure-velocity compounded turbine
b) simple reaction turbine
c) velocity compounded turbine
d) pressure compounded turbine

View Answer

Answer: d [Reason:] A Rateau turbine is a pressure compounded turbine.

10. When the cross-section of a nozzle increases continuously from entrance to exit, it is called a
a) convergent-divergent nozzle
b) divergent nozzle
c) convergent nozzle
d) none of the mentioned

View Answer

Answer: b [Reason:] When the cross-section of a nozzle increases continuously from entrance to exit, it is called a divergent nozzle.