## [MCQ’s] Power Engineering

#### Module 01

1. Internal energy of combustion products is ______________ than that of reactants.
a) less
b) more or less (depends on state of fuel)
c) same
d) more
Explanation: The internal energy of combustion is given by uRP=UP-UR which gives a negative value.

2. Higher efficiency in combustion of solid fuel cannot be achieved by ___________
a) keeping flue gas temperature very high
b) proper fuel preparation
c) supplying correct quantity of combustion air
d) adopting efficient fuel-firing technique and equipment
Explanation: Keeping flue gas temperature very high does not result in increased efficiency of solid fuel.

3. Bomb calorimeter is used determine the calorific value of ___________
a) solid fuels
b) liquid fuels
c) both solid and liquid fuels
d) none of the mentioned
Explanation: Bomb calorimeter can be used to determine the calorific value of both solid and liquid fuels.

4. Which of these is not a reason for reduction in maximum flame temperature in actuality?
a) incomplete combustion
b) heat loss to exhaust gases
c) excess air requirements
d) heat loss to surroundings
Explanation: Maximum flame temperature is defined on the temperature of products; hence it cannot be a reason for reduction in flame temperature.

5. Grindability index of a coal is 100. It implies that the __________
a) coal can be easily pulverised
b) coal can be pulverised with great difficulty
c) coal can’t be pulverised
d) power consumption in grinding the coal will be very high
Explanation: Grindability of an object is the ease with which the object can be reduced into powdered form. A measure of the same is the Grindability index of coal.

6. Tar yield in the low temperature and high temperature carbonisation of dry coal may be respectively __________ percent.
a) 10 & 3
b) 3 & 10
c) 15 & 8
d) 10 & 20
Explanation: Tar yield in the low temperature and high temperature carbonisation of dry coal may be respectively 10 & 3 percent.

7. High amount of sulphur and phosphorous in coke causes __________
a) decrease in its calorific value
b) increase in its strength
c) brittleness of steel made by using it
d) none of the mentioned
Explanation: None of the effects are caused by the increased strength of sulphur & phosphorus in coke.

8. The difference between the enthalpy of products & the enthalpy of reactants when complete combustion occurs at specific temperature & pressure is called?
a) Enthalpy of burning
b) Enthalpy of Combustion
c) Enthalpy of complete combustion
d) None of the mentioned
Explanation: Enthalpy of Combustion is defined as, “The difference between the enthalpy of products & the enthalpy of reactants when complete combustion occurs at specific temperature & pressure”.

9. The internal energy of products minus the internal energy of reactants for complete combustion at specific temperature & pressure gives the internal energy of?
a) combustion
b) partial combustion
c) complete combustion
d) none of the mentioned
Explanation: The internal energy of products minus the internal energy of reactants is called the internal energy of combustion.

10. HCV stands for?
a) Higher Combustion Value
b) Higher Convection Value
c) Higher Calorific Value
d) Higher Calorific Value
Explanation: HCV is an acronym for High Calorific Value.

11. The heat transferred when the H2O in the products is in the liquid state is called?
a) HCV
b) LCV
c) LHV
d) None of the mentioned
Explanation: The heat transferred when the H2O in the products is in the liquid state is called HCV [Higher Calorific Value].

12. The heat transferred when the H2O in the products is in the vapour state is called?
a) HCV
b) LCV
c) HHV
d) None of the mentioned
Explanation: The heat transferred when the H2O in the products is in the vapour state is called LCV [Lower Calorific Value].

13. The maximum temperature achieved for given reactants is called?
a) Practical Flame Temperature
b) Critical Temperature
c) Theoretical Flame Temperature
d) None of the mentioned
Explanation: Theoretical Flame Temperature is the maximum temperature achieved for given reactants.

14. Maximum Theoretical Flame Temperature corresponds to _____________
a) Partial Combustion
b) Incomplete Combustion
c) Complete combustion
d) None of the mentioned
Explanation: Maximum Theoretical Flame Temperature corresponds to Complete Combustion.

15. In pure oxygen, the maximum flame temperature is _____________
a) higher than the theoretical flame temperature
b) lower than the theoretical flame temperature
c) equal to the theoretical flame temperature
d) none of the mentioned
Explanation: In pure oxygen, the maximum flame temperature is higher than the theoretical flame temperature because of dilution effect of Nitrogen.

16. Maximum permissible temperature in a gas turbine is?
a) Fixed
b) Variable
c) Linearly increasing
d) Linearly decreasing
Explanation: Maximum permissible temperature in a gas turbine is Fixed from metallurgical considerations.

17. Dissociation is directly proportional to temperature.
a) True
b) False
Explanation: Dissociation is directly proportional to temperature as when the temperature increases, the amount of dissociation also increases & vice-versa.

18. Spontaneity of a chemical reaction depends on?
a) Enthalpy of reaction
b) Energy of reaction
c) Gibbs Free Energy
d) None of the mentioned
Explanation: Gibbs free energy is the parameter which determines the spontaneity of the reaction after determining its randomness.

19. For exothermic reactions, free energy change is?
a) positive
b) negative
c) zero
d) none of the mentioned
Explanation: Gibbs free energy is the parameter which determines the spontaneity of the reaction after determining its randomness. For exothermic reactions, this energy difference has to be negative.

#### Module 02

1. How can we classify steam generators on the basis of application?
a) utility steam generators
b) industrial steam generator
c) marine steam generator
d) all of the mentioned
Explanation: Steam generators can be classified in a number of ways, on the basis of application these three generators are known.

2. What is the critical pressure of steam?
a) 221.2 bar
b) 220 bar
c) 120 bar
d) 300 bar
Explanation: Below 221.2 its sub critical and above 221.2 its super critical.

3. An air preheater is installed _____________
a) between the economiser and chimney
b) before the superheater
c) before the economiser
d) none of the mentioned
Explanation: Preheater is used to increase the temperature of steam.

4. What is the length of shell of a Locomotive boiler?
a) 5m
b) 4m
c) 3m
d) 2m
Explanation: It is fixed due to mechanical constraints.

5. Which of the following statement is correct?
a) A simple vertical boiler has one fire tube
b) A fire tube boiler occupies less space than a water tube boiler, for a given power
c) Steam at a high pressure and in large quantities can be produced with a simple vertical boiler
d) all of the mentioned
Explanation: A typical vertical boiler can have only one fire tube for the flow of fire or heat.

6. The object of producing draught in a boiler is _________
a) to discharge the gases of combustion to the atmosphere through the chimney
b) all of the mentioned
c) to exhaust the gases of combustion from the combustion chamber
d) to provide an adequate supply of air for the fuel combustion
Explanation: None.

7. The natural draught is produced by _________
a) team jet
b) chimney
c) centrifugal fan
d) none of the mentioned
Explanation: When air or flue gases flow due to the difference in density of the hot flue gases and cooler ambient gases.

8. Which of the following statement is wrong?
a) Water tube boilers are internally fired
b) Locomotive boiler is a water tube boiler
c) La-mont boiler is a low pressure water tube boiler
d) All of the mentioned
Explanation: Water tube boilers are externally fired where as fire tube boilers are internally fired.

9. Which of the following boiler is best suited to meet the fluctuating demand of steam?
a) Locomotive boiler
b) Lancashire boiler
c) Babcock and Wilcox boiler
d) Cornish boiler
Explanation: Because forced draught is provided in the locomotive boiler by injecting exhausted steam back into the exhaust via a blast pipe in the smokebox.

10. In a fire-tube boiler, the water is in ___________
a) tube
b) shell
c) drum
d) all of the mentioned
Explanation: A fire-tube boiler is one in which the hot flue gases flow through the tubes surrounded by water in a shell.

11. Which of the following auxiliaries are not used in steam Generators?
a) economiser
b) burner
c) fan
d) stoker
Explanation: Burner, fan, stoker, pulverisers, etc. are the various auxiliaries that are used in steam generators.
An economiser is a part of the steam generation plant.

12. The formation of scale boiler leads to _________
a) decrease in efficiency of boiler
b) increase in efficiency of boiler
c) increase in heat transfer
d) decrease in maintenance of boiler
Explanation: Efficiency of boiler is inversely proportional to the scale formation.

13. What is the pH value of water permissible for boiler?
a) 0
b) 7
c) slightly less than 7
d) slightly more than 7
Explanation: The pH value of water used in the boiler is slightly greater than 7 for most of the commonly used boiler.

14. Which device used to separate condensate from the steam without letting steam escape?
a) condenser
b) steam valve
c) steam trap
d) none of the mentioned
Explanation: The steam trap is a device that is used to separate condensate from the steam without letting steam escape.

15. What is the disadvantage of natural draught?
a) it has less life
b) it has more maintenance cost of cleaning and more capital cost to build the chimney
c) the available draught decreases with increasing outside air temperature
d) all of the mentioned

16. The natural draught in the steam generator depends upon _________
a) the air condition outside the chimney
b) the temperature of exhaust gases
c) the air condition outside the chimney & the temperature of exhaust gases
d) none of the mentioned
Explanation: The natural draught in the steam generator depends upon the air condition outside chimney & the temperature of the exhaust gases.

17. What is the purpose of super heater in a boiler?
a) to increase the temperature of saturated steam with increase in its pressure
b) to increase the temperature of saturated steam without increase in its pressure
c) to increase the temperature of feedwater for better efficiency
d) none of the mentioned
Explanation: Superheater in a boiler has the function of increasing the temperature of saturated steam without increase in its pressure.

18. How is the natural draught produced for exhaust gases?
a) by using fan
b) by using chimney
c) by using gravity
d) none of the mentioned
Explanation: The natural draught is produced for exhaust gases by using chimney.

19. What is the purpose of using economizer in the boiler?
a) to heat feed water by utilizing heat from exhaust gases
b) to heat feed water by utilizing some heat from superheated steam
c) to superheat steam
d) none of the mentioned
Explanation: The use of Economiser in a boiler is to heat the feed water by utilizing heat from exhaust gases.

20. Comparing fire tube and water tube boilers, which boiler can produce comparatively higher pressure steam than another for the same capacity?
a) fire tube boiler
b) water tube boiler
c) both can produce steam at same pressure for the same capacity
d) none of the mentioned
Explanation: A water tube boiler can produce comparatively higher pressure steam than another for the same capacity.

21. The boiler in which the tubes are surrounded by hot gases is called ___________
a) fire tube boiler
b) water tube boiler
c) both fire and water tube boiler
d) none of the mentioned
Explanation: A water tube boiler is a boiler in which the cool water containing water tubes are surrounded by hot gases.

22. Which of these is not a type of steam generator depending upon the kind of applications?
a) utility steam generators
b) marine steam generators
c) agricultural steam generators
d) industrial steam generators
Explanation: There are three types of steam generators depending upon the type of application which are utility, industrial & marine steam engines.

23. What is the critical pressure of steam in a utility steam generator?
a) 220.2 bar
b) 221.2 bar
c) 222.2 bar
d) 225.2 bar
Explanation: The critical pressure of steam in a utility steam generator is 221.2 bar.

24. Which of the following are drumless once-through steam generators?
a) Subcritical steam generator
b) Supercritical steam generators
c) Utility steam generators
d) Marine steam generators
Explanation: Supercritical steam generators are drumless once-through steam generators while the subcritical steam generators are the water-tube drum type ones.

25. The subcritical steam generators operate between a pressure ranges of ___________
a) 120-160 bar
b) 100-110 bar
c) 130-180 bar
d) 140- 200 bar
Explanation: The subcritical steam generators operate between a pressure range of 130-180 bar.

26. The supercritical steam generators operate at a pressure range of ___________
a) 200-240 bar
b) 200-220 bar
c) 220- 240 bar
d) >240 bar
Explanation: The supercritical steam generators operate at a pressure range of more than 240 bar.

27. Industrial steam generators operate in a pressure range of ___________
a) 5-105 bar
b) 6-106 bar
c) <5 bar
d) >105 bar
Explanation: Industrial steam generators operate in a pressure range of 5-105 bar.

28. Industrial steam generators operate at a steam capacity of ___________
a) 1300 kg/s
b) 1000 kg/s
c) 500 kg/s
d) 125 kg/s
Explanation: Industrial steam generators operate at a steam capacity of about 125 kg/s which is lesser than that of utility steam generators.

29. Marine steam generators are ___________ fired.
a) water
b) oil
c) phenol
d) none of the mentioned
Explanation: Marine steam generators are oil-fired.

30. What is the pressure range between which a marine steam generator works?
a) 100-200 bar
b) 60-65 bar
c) 80-100 bar
d) 70-85 bar
Explanation: The pressure range between which a marine steam generator works is 60-65 bar.

31. Fire-tube boilers are used in?
a) industrial steam generators
b) utility steam generators
c) marine steam generators
d) none of the mentioned
Explanation: Industrial steam generators use fire-tube boilers as they suit the most for the quantity of steam in the industrial steam generators.

32. Which of the following is not an advantage of a fire-tube boiler?
a) low first cost
b) reliability in operation
c) more draught required
d) quick response to load changes
Explanation: The advantages of using a fire tube boiler are low first cost, reliability in operation, less draught required, quick response to load changes, etc.

33. Which of these is a type of fire-tube boiler?
a) Externally fired
b) Internally fired
c) Internally & Externally fired
d) None of the mentioned
Explanation: There are two types of a fire-tube boiler which are Internally & Externally fired boilers.

34. Which of these is an externally fired boiler?
a) Package boiler
b) Scotch-marine boiler
c) Lancashire boiler
d) None of the mentioned
Explanation: The various types of externally fired boiler include Lancashire boilers, Locomotive type boilers, HRT boiler, etc.

35. Which of the following is a type of internally fired boiler?
a) Package boiler
b) HRT boiler
c) Lancashire boiler
d) Locomotive type boiler
Explanation: The various types of an internally fired boiler include Scotch-marine boiler, Package boiler, etc.

36. What is the function of the fusible plug installed in a furnace?
a) to detect excess current
b) to detect excess heat
c) to detect water level in the tube
d) to detect water level in the shell
Explanation: Water level in the shell is detected by the fusible plug installed in the crown of the furnace.

37. Which of the following gaseous fuels has the lowest calorific value?
a) Refinery Gas
b) Gobar Gas
c) Converter Gas
d) Blast Furnace Gas
Explanation: The lowest calorific value fuel means a fuel which burns most readily. Among all the given options, the most combustible gas is the blast furnace gas.

38. Fuel gases containing hydrocarbons (e.g. coke oven gas) are not preheated before burning, mainly because ____________
a) there are chances of explosion during preheating
b) it reduces its calorific value tremendously
c) the hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot
d) it reduces its flame temperature tremendously
Explanation: Fuel gases containing hydrocarbons (i.e. coke oven gas) are not preheated before burning, mainly because the hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot.

39. Flue gas discharge velocity through chimney of a big thermal power plant may be around __________ m/sec.
a) 500
b) 0.5
c) 10
d) 50
Explanation: The velocity of discharge of flue gases through the chimney of a big thermal power plant is around 10 m/sec.

40. In water tube boilers ___________
a) forced circulation takes place
b) water passes through the tubes which are surrounded by flames and hot gases
c) the flames and hot gases pass through the tubes which are surrounded by water
d) none of the mentioned
Explanation: In water tube boilers the flames and hot gases pass through the tubes which are surrounded by water.

41. The object of producing draught in a boiler is ___________
a) to provide an adequate supply of air for the fuel combustion
b) to exhaust the gases of combustion from the combustion chamber
c) to discharge the gases of combustion to the atmosphere through the chimney
d) all of the mentioned
Explanation: The objectives of producing draught in a boiler are providing an adequate supply of air for the fuel combustion, to vent the exhaust gases of combustion from combustion chamber to the atmosphere via chimney.

42. What is the function of a piston rod?
a) to transfer motion from the piston to the cross head
b) to convert heat energy of the steam into mechanical work
c) to guide motion of the piston rod and to prevent it from bending
d) to exhaust steam from the cylinder at proper moment
Explanation: Piston rod transfers motion from the piston to the cross head.

43. The cylinder dimensions of a compound engine may be designed on the basis of ___________
a) equal initial piston loads on all pistons for obtaining same size of piston rod, connecting rod etc. for all cylinders
b) equal power developed in each cylinder for uniform turning moment
c) equal temperature drop in each cylinder for economy of steam
d) all of the mentioned
Explanation: The cylinder dimensions of a compound engine may be designed on the basis of equal temperature drop in each cylinder for economy of steam, equal power developed per cylinder for uniform turning moment, equal initial positions for all pistons.

44. The function of a crosshead is to guide motion of the __________ and to prevent it from bending.
a) valve rod
b) eccentric rod
c) connecting rod
d) piston rod
Explanation: The function of a crosshead is to guide motion of the piston rod and to prevent it from bending.

45. Which of the following statement is wrong?
a) The amount of water evaporated in kg per kg of fuel burnt is called equivalent evaporation from and at 100° C
b) The ratio of heat actually used in producing the steam to the heat liberated in the furnace is called boiler efficiency
c) The factor of evaporation for all boilers is always greater than unity
d) None of the mentioned
Explanation: All the given statements are true.

46. A device used to increase the temperature of saturated steam without raising its pressure is called?
a) fusible plug
b) blow off cork
c) super heater
d) stop valve
Explanation: Super heater is the device used to increase the temperature of saturated steam without raising its pressure.

47. A safety valve usually employed with stationary boilers is ___________
a) high steam and low water safety valve
b) dead weight safety valve
c) lever safety valve
d) all of the mentioned
Explanation: The safety valve can also be called as high/low steam safety valve, dead weight safety valve, lever safety valve.

48. Fire tube boilers are ___________
a) internally fired
b) externally fired
c) both internally as well as externally fired
d) none of the mentioned
Explanation: fire-tube boiler is an internally fired boiler.

49. The diameter of flue tube in a Cornish boiler is __________ that of the shell.
a) 3/5
b) 2/5
c) 1/3
d) 1/4
Explanation: The diameter of flue tube in a Cornish boiler is 3/5 of that of the shell.

50. Which of the following statement is correct?
a) A simple vertical boiler has one fire tube
b) Steam at a high pressure and in large quantities can be produced with a simple vertical boiler
c) A fire tube boiler occupies less space than a water tube boiler, for a given power
d) All of the mentioned
Explanation: “A simple vertical boiler has one fire tube” is the wrong statement.

51. When the circulation of water, in a boiler, is by a centrifugal pump, then the boiler is known as _____________
a) forced circulation boiler
b) externally fired boiler
c) naturally circulation boiler
d) internally fired boiler
Explanation: When the circulation of water, in a boiler, is by a centrifugal pump, then the boiler is known as forced circulation boiler.

52. A single acting steam engine produces __________ power than that of double acting steam engine.
a) equal
b) double
c) half
d) 4 times
Explanation: A single acting steam engine produces half power than that of double acting steam engine.

53. Cut-off governing of steam engines is a method of controlling the engine output by varying __________
a) volume of intake steam
b) pressure of intake steam
c) temperature of intake steam
d) all of the mentioned
Explanation: Cut-off governing of steam engines is a method of controlling the engine output by varying volume of intake steam.

54. A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose is known as __________
a) air preheater
b) superheater
c) injector
d) none of the mentioned
Explanation: A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is knwon as air-preheater.

55. Which of the following statement is correct?
a) Fire tube boilers are internally fired
b) Lancashire boiler is a fire tube boiler
c) Babcock and Wilcox boiler is a water tube boiler
d) All of the mentioned
Explanation: All the mentioned statements are correct.

56. In a uniflow engine __________
a) steam enters and exhausts through the same port
b) steam enters at one end and exhausts at the centre
c) steam enters at the centre and exhausts at the other end
d) none of the mentioned
Explanation: Steam enters at one end and exhausts at the centre in a Uniflow engine.

57. A safety valve mainly used with locomotive and marine boilers is __________
a) lever safety valve
b) dead weight safety valve
c) spring loaded safety valve
d) high steam and low water safety valve
Explanation: A safety valve mainly used with locomotive and marine boilers is spring loaded safety valve.

58. The power of a boiler may be defined as __________
a) the amount of water evaporated or steam produced in kg per kg of fuel burnt
b) the ratio of heat actually used in producing the steam to the heat liberated in the furnace
c) the evaporation of 15.653 kg of water per hour from and at 100° C
d) the amount of water evaporated from and at 100° C into dry and saturated steam
Explanation: The power of a boiler may be defined as the amount of water evaporated or steam produced in kg per kg of fuel burnt.

59. Which of the following boiler is best suited to meet the fluctuating demand of steam?
a) Cornish boiler
b) Lancashire boiler
c) Locomotive boiler
d) Babcock & Wilcox boiler
Explanation: Locomotive Boiler is the best suited to meet the fluctuating demand of steam.

60. The diameter of Cornish boiler varies from __________
a) 1 to 2m
b) 0.5 to 1m
c) 1.25 to 2.5m
d) 2 to 3m
Explanation: The diameter of Cornish Boiler varies from 1-2 m.

61. A steam turbine converts the output from a steam generator into ____________
a) Shaft work
b) Turbine work
c) Mechanical work
d) None of the mentioned
Explanation: A steam turbine is a device that converts the energy of high-pressure, high-temperature steam supplied by a steam generator into shaft work.

62. The energy conversion occurring in a steam turbine is a ______ step process.
a) 1
b) 2
c) 3
d) 4
Explanation: The high pressure steam first expands in a nozzle, gains velocity & then loses this velocity when it impinges on the blades.

63. A steam turbine is basically an assemblage of ____________
a) nozzle & condenser
b) blades & condenser
c) nozzle & blades
d) nozzle & fans
Explanation: A steam turbine is a device that converts the energy of high-pressure, high-temperature steam supplied by a steam generator into shaft work. The high pressure steam first expands in a nozzle, gains velocity & then loses this velocity when it impinges on the blades.

64. Depending on whether the back pressure is below or equal to the atmospheric pressure, how many types of turbines do exist?
a) 1
b) 2
c) 3
d) 4
Explanation: Depending on whether the back pressure is below or equal to the atmospheric pressure, there are two types of turbines that exist- condensing & non-condensing turbines.

65. The overall steam turbine generator arrangement of a power plant is designated as ________ compound on the basis of shaft orientation.
a) tandem
b) cross
c) tandem & cross
d) none of the mentioned
Explanation: The overall steam turbine generator arrangement of a power plant is designated as tandem or cross-compound on the basis of shaft orientation.

66. A ______ is a duct through which velocity of a fluid increases at the expense of pressure.
a) orifice
b) nozzle
c) jet
d) diffuser
Explanation: A nozzle is a duct through which the velocity of a fluid increases at the expense of pressure.

67. A duct which decreases the velocity of fluid & causes a corresponding increase in pressure is called?
a) nozzle
b) diffuser
c) jet
d) orifice
Explanation: A duct which decreases the velocity of fluid & causes a corresponding increase in pressure is called a diffuser.

78. A regenerative steam cycle renders ____________
a) decreased work output per unit mass of steam
b) increased thermal efficiency
c) increased work output per unit mass of steam
d) decreased work output per unit mass of steam as well as increased thermal efficiency
Explanation: The decreased work output per unit mass of steam as well as increased thermal efficiency.

69. The reheat factor is the ratio of the ____________
a) total useful heat drop to the total isentropic heat drop
b) cumulative heat drop to the isentropic heat drop
c) isentropic heat drop to the heat supplied
d) none of the mentioned
Explanation: The ratio of cumulative heat drop to the isentropic heat drop is called the reheat factor.

70. Thermal equilibrium means that the flow of steam is ____________
a) hyperbolic
b) isothermal
c) isentropic
d) polytropic
Explanation: When the steam flow is isentropic it is thermal equilibrium condition.

#### Module 03

1. Addition of an infinitesimal amount of heat at the highest temperature is because ___________
a) to initiate reheating
b) to initiate regeneration
c) to initiate superheating
d) none of the mentioned
Explanation: The maximum temperature gained in steam cycles using the best available material is about 600 degree Celsius while the critical temperature of steam is about 375 degree Celsius, which necessitates large superheating and permits addition of an infinitesimal amount of heat at the highest temperature.

2. High moisture content is involved during expansion of steam because ___________
a) to ensure uniform heating
b) to ensure uniform cooling
c) to obtain a higher temperature of heat addition
d) to obtain a lower temperature of heat addition
Explanation: In order to obtain a higher temperature of heat addition, heat moisture content is involved during expansion of steam.

3. What is the relation of the mean temperature of heat addition and cycle efficiency?
a) both are inversely proportional
b) both are directly proportional
c) both are independent of each other
d) none of the mentioned
Explanation: The cycle efficiency is a function of mean temperature of heat addition. Hence, both are directly proportional to each other. The need for high pressure is only forced due to weak characteristics of steam.

4. Temperature of heat rejection in a condenser can be lowered by using?
a) lubricant
b) oil
c) refrigerant
d) diesel
Explanation: A refrigerant in the form of coolant is used to lower the temperature of heat rejection.

5. The use of which of the following becomes necessary during expansion of steam?
a) reheat
b) regeneration
c) refrigeration
d) superheat
Explanation: In order to obtain a higher temperature of heat addition, heat moisture content is involved during expansion of steam. The use of reheat thus becomes necessary.

6. Which is the drawback of the steam as a working substance in a power cycle?
a) in a vapour power cycle, maximum temperature which can be obtained with best available material is more than the critical temperature of water and requires large superheating
b) it allows only small amount of heat addition at the highest temperature
c) it requires reheat and reheater tubes are costly
d) all of the mentioned
Explanation: All the drawbacks mentioned are correct.

7. For maximum efficiency of vapour power cycle, what should be the critical temperature of working fluid?
a) the working fluid should have critical temperature as low as possible
b) the working fluid should have critical temperature as high as possible
c) the critical temperature does not affect the efficiency of the vapour power cycle
d) none of the mentioned
Explanation: More the critical temperature, more efficient will be the working.

8. What is the specific heat of the ideal working fluid used in vapour power cycle?
a) should be constant
b) should be large
c) should be small
d) none of the mentioned
Explanation: The specific heat of a fluid is the amount of energy the fluid takes in heating water for 1 degree Celsius.

9. What is the importance of the freezing point of the working fluid in the vapour power cycle?
a) freezing point of working fluid should be below the room temperature
b) freezing point of working fluid should be above the room temperature
c) freezing point of working fluid should be equal to the room temperature
d) does not have any importance
Explanation: For the efficient working of a working fluid, its freezing point should be below the room temperature.

10. When two vapour cycles are coupled in series and heat rejected by one is absorbed by another, the cycle is called as?
a) Dual vapour cycle
b) Binary vapour cycle
c) Coupled vapour cycle
d) None of the mentioned
Explanation: Binary vapour cycle is a cycle where two vapour cycles are coupled in series and heat rejected by one is absorbed by another.

11. What is the air standard cycle for a Gas-Turbine called?
a) Reheat cycle
b) Rankine cycle
c) Brayton cycle
d) Diesel cycle
Explanation: Brayton cycle is an ideal air standard cycle for a Gas turbine, which, like the Rankine cycle, also comprises of two reversible adiabatic & two reversible isobars.

12. What is the difference between a Rankine cycle & a Brayton cycle?
a) working fluid in a Brayton cycle undergoes phase change while it doesn’t in Rankine cycle
b) working fluid in a Brayton cycle doesn’t undergo phase change while it does in Rankine cycle
c) both are same
d) none of the mentioned
Explanation: The difference between a Rankine cycle & a Brayton cycle is that the working fluid in a Brayton cycle doesn’t undergo phase change while it does in Rankine cycle.

13. Which of the following is a type of Gas Turbine Plant?
a) Single Acting
b) Double Acting
c) Open
d) None of the mentioned
Explanation: Open & Closed Gas Turbine plants are the two types.

14. Power is produced when the working fluid does some work on the?
a) Shaft
b) Fins
d) None of the mentioned
Explanation: For the production of power, the working fluid does some work on the blades of the turbine, thereby producing Power.

15. A Gas Turbine is which type of combustion plant?
a) external
b) open
c) internal
d) cannot say
Explanation: Since for the production of power, the working fluid does some work on the blades of the turbine, thereby producing Power. Hence, it is called an internal combustion plant.

16. Which among these is the main component of a gas turbine plant?
a) Condenser
b) Compressor
c) Boiler
d) Both Compressor & Boiler
Explanation: The main component of a Gas turbine plant is Compressor.

17. Which type of compressor is used in a gas turbine plant?
a) Reciprocating compressor
b) Screw compressor
c) Multistage axial flow compressor
d) Either Reciprocating compressor & Screw compressor
Explanation: Multistage axial flow compressor is the compressor in practical usage in a gas turbine plant.

18. What part or % of power developed is utilised for driving the compressor?
a) 65 %
b) 70 %
c) 55 %
d) 80 %
Explanation: A total of 65 % of power developed in the gas turbine is used for driving the compressor.

19. The gas turbine power plant mainly uses which among the following fuels?
a) Coal and Peat
b) Kerosene oil and diesel oil and residual oil
c) Gas oil
d) Natural gas and liquid petroleum fuel
Explanation: Natural gas and liquid petroleum fuel are among the two fuels used in a gas turbine.

20. The engines which are operating on gas power cycle are?
a) cyclic
b) non-cyclic
c) either cyclic or non-cyclic
d) none of the mentioned
Explanation: The cyclic nature is totally dependent on power cycle; it can be cyclic as well as non-cyclic depending on the gas power cycle.

21. The heating value of gaseous fuels is about _____________
a) 500 kJ/litre
b) 30 kJ/litre
c) 100 kJ/litre
d) 10 kJ/litre
Explanation: 30 kJ/litre is the heating value of gaseous fuels.

22. The compressor has to be started _____________
a) Before starting the gas turbine
b) After starting the gas turbine
c) Simultaneously with starting of gas turbine
d) At any time during the operation
Explanation: Compressor has to be started before starting the gas turbine as the turbine work is used by compressor.

23. Which of these is not a part of a Gas Turbine Plant?
a) Compressor
b) Gas Turbine
c) Combustion chamber
d) Boiler
Explanation: A Gas Turbine Plant has the following parts:
Compressor, Gas Turbine, Combustion chamber.

24. What are the major field(s) of application of gas turbine?
a) Aviation
b) Oil and gas industry
c) Marine propulsion
d) All of the mentioned
Explanation: A Gas Turbine has applications in nearly all fields, the major ones being in the fields of Aviation, Oil & Gas industry, Marine propulsion.

25. Which of the following is (are) the limitation(s) of gas turbines?
a) They are not self-starting
b) Higher rotor speeds
c) Low efficiencies at part loads
d) All of the mentioned
Explanation: The limitations in the functioning of a Gas Turbines are inability of self-starting, excess rotor speeds and inability to adjust to varying loads.

26. The ratio of heat actually released by 1kg of fuel to heat that would be released by complete perfect combustion is called ___________
a) Thermal efficiency
b) Combustion efficiency
c) Engine efficiency
d) Compression efficiency
Explanation: Combustion efficiency is defined as,” The ratio of heat actually released by 1kg of fuel to heat that would be released by complete perfect combustion”.

27. What is the percentage of total energy input appearing as network output of the cycle?
a) Thermal efficiency
b) Combustion efficiency
c) Engine efficiency
d) Compression efficiency
Explanation: Thermal Efficiency is, “The percentage of total energy input appearing as network output of the cycle”.

28. Which of the following method(s) can be used to improve the thermal efficiency of open cycle gas turbine plant?
a) Inter-cooling
b) Reheating
c) Regeneration
d) All of the mentioned
Explanation: The various methods to improve the efficiency of open cycles include intercooling the feed water from the compressor to the turbine and then employing regeneration & reheat to just use the power of the reheated water in order to maximize the power output.

29. Which of the following is (are) used as starter for a gas turbine?
a) An Internal combustion engine
b) A steam turbine
c) An auxiliary electric motor
d) All of the mentioned
Explanation: There are various methods by which a Gas Turbine can be started, they are by the use of an Internal Combustion engine, a steam turbine, an auxiliary electric motor, etc.

30. Gas turbine is shut down by ____________
a) Turning off starter
b) Stopping the compressor
c) Fuel is cut off from the combustor
d) All of the mentioned
Explanation: The only way to stop a running Gas turbine is by cutting off the fuel supply so that the various processes in the cycle are stopped.

31. In gas turbine, intercooler is placed _____________
a) before low pressure compressor
b) in between low pressure compressor and high pressure compressor
c) in between high pressure compressor and turbine
d) none of the mentioned
Explanation: The various methods to improve the efficiency of open cycles include intercooling the feed water from the compressor to the turbine and then employing regeneration & reheat to just use the power of the reheated water in order to maximize the power output. Here, this is done by placing the intercooler before any of the above processes.

32. In gas turbine, what is the function of Re-heater?
a) Heat inlet air
b) Heat exhaust gases
c) Heat air coming out of compressor
d) Heat gases coming out of high pressure turbine
Explanation: In order to make a thermodynamic process of larger efficiency, it is shifted towards isothermal behavior. For this, the output from re-generator, which is at a higher temperature is cooled to the temperature which is mid-way between the two temperature ranges. Then, it is again heated to the final temperature thereby increasing the efficiency of the cycle.

33. The ‘work ratio’ increases with _____________
a) increase in turbine inlet pressure
b) decrease in compressor inlet temperature
c) decrease in pressure ratio of the cycle
d) all of the mentioned
Explanation: The ‘work ratio’ increases when the turbine inlet pressure increases, the compressor inlet temperature decreases, the pressure ratio of the cycle decreases.

34. In the centrifugal compressor, total pressure varies _____________
a) directly as the speed ratio
b) square of speed ratio
c) cube of the speed ratio
d) all of the mentioned
Explanation: The total pressure in a centrifugal compressor is a function of speed ratio. It varies square of the speed ratio.

35. The efficiency of multistage compressor is _____ than a single stage.
a) lower
b) higher
c) equal to
d) all of the mentioned
Explanation: The efficiency of multistage compressor is lower than a single stage.

36. In centrifugal compressor, power input varies as _________
a) directly as the speed ratio
b) the square of speed ratio
c) the cube of the speed ratio
d) all of the mentioned
Explanation: Power output in a centrifugal compressor varies as the cube of the speed ratio.

37. In the ____________ heat transfer takes place between the exhaust gases and cool air.
a) Intercooler
b) Re-heater
c) Regenerator
d) Compressor
Explanation: The process of heat transfer between the exhaust gases and cool air takes place in Regenerator.

38. In centrifugal compressor, the diffuser converts _________
a) Kinetic energy into pressure energy
b) Pressure energy into Kinetic energy
c) Kinetic energy into Mechanical energy
d) Mechanical energy into Kinetic energy
Explanation: The diffuser of a centrifugal compressor converts Kinetic Energy into Pressure energy.

#### Module 04

1. In a four stage compressor, if the pressure at the first and third stage are 1 bar and 16 bar, then the delivery pressure at the fourth stage will be
A.1 bar
B.16 bar
C.64 bar
D.256 bar

2. The compressed air may be used
A.in gas turbine plants
B.for operating pneumatic drills
C.in starting and supercharging of I.C. engines
D.all of the above

3. A rocket works with maximum overall efficiency when air-craft velocity is __________ the jet velocity.
A.equal to
B.one-half
C.double

4. The volumetric efficiency for reciprocating air compressors is about
A.10 to 40%
B.40 to 60%
C.60 to 70%
D.70 to 90%

5. The maximum temperature in a gas turbine is
A.200°C
B.500°C
C.700°C
D.1000°C

6. The rotary compressors are suitable for large discharge of air at low pressure.
A.True
B.False

7. The stagnation pressure rise in a centrifugal compressor takes place
A.in the diffuser only
B.in the impeller only
C.in the diffuser and impeller
D.in the inlet guide vanes only

8. The total heat rejected in a reciprocating air compressor is equal to the sum of the heat rejected during polytropic compression per kg of air and heat rejected in the intercooler per kg of air.
A.True
B.False

9. In a jet propulsion
A.the propulsive matter is ejected from within the propelled body
B.the propulsive matter is caused to flow around the propelled body
C.its functioning does not depend upon presence of air
D.none of the above

10. An open cycle gas turbine works on the same cycle as that of a closed cycle gas turbine.
A.Yes
B.No

11.Which of the following statement is wrong?
A.In a two stage reciprocating air compressor with complete intercooling, maximum work is saved.
B.The minimum work required for a two stage reciprocating air compressor is double the work required for each stage.
C.The ratio of the volume of free air delivery per stroke to the swept volume of the piston is called volumetric efficiency.
D.none of the above

12. In a single acting reciprocating compressor, the suction, compression and delivery of air takes place in __________ of the piston.
A.one stroke
B.two strokes
C.three strokes
D.four strokes

13. The increase in pressure in a vane blower takes place first due to compression and then due to back flow of air.
A.Correct
B.Incorrect

14. The maximum delivery pressure in a rotary air compressor is
A.10 bar
B.20 bar
C.30 bar
D.50 bar

15. The capacity of a compressor is expressed in
A.kg/m2
B.kg/m3
C.m3/min
D.m3/kg

16.Intercooling in multi-stage compressors is done
A.to cool the air during compression
B.to cool the air at delivery
C.to enable compression in two stages
D.to minimise the work of compression

17. For a two stage reciprocating compressor, compression from p1 to p3 is with perfect intercooling and no pressure losses. If compression in both the cylinders follows the same polytropic process and the atmospheric pressure is pa, then the intermediate pressure p2 is given by 18. The ratio of workdone per cycle to the stroke volume of the compressor is known as
A.compressor capacity
B.compression ratio
C.compressor efficiency
D.mean effective pressure

19. The clearance volume in the compressor is kept minimum because it effects on volumetric efficiency.
A.Correct
B.Incorrect

20. The inlet pressure is always __________ the discharge pressure.
A.equal to
B.less than
C.more than

21. Which of the following statement is correct?
A.The ratio of the discharge pressure to the inlet pressure of air is called compressor efficiency.
B.The compression ratio for the compressor is always greater than unity.
C.The compressor capacity is the ratio of workdone per cycle to the stroke volume.
D.During isothermal compression of air, the workdone in a compressor is maximum.

22. In the aircraft propellers
A.the propulsive matter is ejected from within the propelled body
B.the propulsive matter is caused to flow around the propelled body
C.its functioning does not depend upon the presence of air
D.none of the above

23. The type of rotary compressor used in gas turbines, is of
A.centrifugal type
B.axial flow type
D.none of these

24. The volume of air delivered by the compressor is called
A.free air delivery
B.compressor capacity
C.swept volume
D.none of these

25. The efficiency of a jet engine is higher at
A.low speeds
B.high speeds
C.low altitudes
D.high altitudes

#### Module 05

1. Kaplan turbine is _____________
a) axial flow turbine
b) inward flow turbine
c) tangential flow turbine
d) mixed flow turbine
Explanation: In Kaplan turbine water strikes the turbine blades axially. That’s why Kaplan turbine is an axial flow turbine. Kaplan turbines are special type of turbines for low head applications.

2. Pelton turbines are used for __________________
a) medium head applications
b) low head applications
c) in steam power plants
d) for high head applications
Explanation: Pelton turbines are impulse turbines and are suitable for high head low flow plants. Pelton turbines consist of elliptical shaped buckets along its Periphery. Water is released from nozzle to the buckets of turbine.

3. Francis turbines are the type of _____________
a) reaction turbines
b) radial flow turbine
c) impulse turbine
d) axial flow turbine
Explanation: Francis turbines are inward mixed flow type reaction turbines. Such turbines develop power partly due to velocity of water and partly due to difference in pressure acting on the front and back of the runner blades.

4. Operating head of Francis turbine is __________
a) less than 30
b) less than 70 m
c) 30 to 200 m
d) more than 200 m
Explanation: Francis turbines are medium head(30 to 200 m) and medium flow turbines. Using it for low or high head will cause inefficient operation. Their life is about decades so maintenance cost is low.

5. Which of the following is not a reaction turbine?
a) Francis turbine
b) Kaplan turbine
c) Pelton wheel turbine
d) Propeller turbine
Explanation: When the entire pressure of water is converted into kinetic energy in a nozzle and the jet thus formed drives the wheel then the turbine is called impulse turbine. Pelton turbine works in similar way, so it is an impulse turbine. Francis, Kaplan and propeller turbines are reaction turbines.

6. Inside pressure of which of the following turbine is equal to atmospheric pressure?
a) Fixed vane propeller turbine
b) Movable vane propeller turbine
c) Francis turbine
d) Pelton wheel turbine
Explanation: Francis and propeller turbines are totally submerged in water, the turbine casing is full of water. As the water flows through the turbine blades, its pressure changes. Also the discharging water creates negative pressure below the turbine blades. Pelton turbines are fitted in open air and water Jet is forced into its blades by nozzel so it’s inside pressure is equal to atmospheric pressure.

7. Francis turbine is suitable for medium head hydroelectric power plant.
a) True
b) False
Explanation: Francis turbines are medium head and medium flow turbines. Kaplan turbines are low head high flow turbines. Pelton turbines are high head and low flow turbines.

8. Which turbine has highest speed?
a) Pelton wheel turbine
b) Francis turbine
c) Impulse turbine
d) Kaplan turbine
Explanation: Francis turbine has a specific speed of 60 to 300 rpm. Specific speed of Pelton turbine is lowest. Speed of Kaplan turbine is 2 to 3 times more than that of Francis turbine.

9. Governing mechanism used in case of Pelton wheel turbine is ________
a) guide vane
b) nozzle needle
c) control valve
d) dam gates
Explanation: During load variation it is necessary to maintain the speed of the alternator constant. This is achieved by controlling the flow of water entering the turbine by the help of automatic adjustment of guide vanes for reaction turbine and the nozzle needle is in case of impulse turbine. Such an operation of speed regulation called governing and the system used to do this is called governor.

10. Guide vanes are used as governor in Kaplan turbine.
a) True
b) False
Explanation: Guide vanes are used as governor in Francis and Kaplan turbines. These guide vanes controls the flow of water to the turbine and hence governs the speed of rotation of turbine. Under different loading conditions the speed of rotation of turbine is needed to be controlled for constant frequency output.

11. Hydraulic energy is converted into another form of energy by hydraulic machines. What form of energy is that?
a) Mechanical Energy
b) Electrical Energy
c) Nuclear Energy
d) Elastic Energy
Explanation: Hydraulic machines firstly convert the energy possessed by water into mechanical energy. Later it can be transformed into electrical energy.

12. In hydraulic turbines, inlet energy is greater than the outlet energy.
a) True
b) False
Explanation: The operating member which receives energy at the inlet should be more compared to energy at the outlet.

13. Which principle is used in Hydraulic Turbines?
b) Newton’s second law
c) Charles law
d) Braggs law
Explanation: A Hydraulic Machine uses the principle of momentum which states that a force is generated which is utilized in a turbine.

14. Buckets and blades used in a turbine are used to:
a) Alter the direction of water
b) Switch off the turbine
c) To regulate the wind speed
d) To regenerate the power
Explanation: Turbines use blades and buckets to alter the direction of water. It is used to change the momentum of water. As momentum changes, force is produced to rotate the shaft of a hydraulic machine.

15. _______________is the electric power obtained from the energy of the water.
a) Roto dynamic power
b) Thermal power
c) Nuclear power
d) Hydroelectric power
Explanation: The energy from the energy of water is also called hydro power. The electric power so obtained is known as hydroelectric power.

16. Which energy generated in a turbine is used to run electric power generator linked to the turbine shaft?
a) Mechanical Energy
b) Potential Energy
c) Elastic Energy
d) Kinetic Energy
Explanation: The kinetic and potential energies produced are converted to some useful mechanical energy. This part of energy is available to the turbine shaft.

17. Hydraulic Machines fall under the category :
a) Pulverizers
b) Kinetic machinery
c) Condensers
d) Roto-dynamic machinery
Explanation: Hydraulic Machines use the principle of rotation of blades to alter the speed of water. Hence fall under roto dynamic machinery.

18. Which kind of turbines changes the pressure of the water entered through it?
a) Reaction turbines
b) Impulse turbines
c) Reactive turbines
d) Kinetic turbines
Explanation: Reaction turbines which act on water try to change the pressure of the water through its motion.

19. Which type of turbine is used to change the velocity of the water through its flow?
a) Kinetic turbines
b) Axial flow turbines
c) Impulse turbines
d) Reaction turbines
Explanation: In Impulse turbines, potential energy is utilized to convert as kinetic energy thereby changing the velocity of the water through its process.

20. Which type of turbine is a Francis Turbine?
a) Impulse Turbine
b) Screw Turbine
c) Reaction turbine
d) Turgo turbine
Explanation: Francis turbine is a reaction turbine as it changes the pressure of water through its process. Hence it cannot be an impulse turbine.

21. A hydraulic coupling belongs to the category of________
a) Energy absorbing machines
b) Energy generating machines
c) Power absorbing machines
d) Energy transfer machines
Explanation: Hydraulic coupling is a device used for transmitting rotation between shafts by means of acceleration and deceleration of hydraulic fluid.

22. The electric power which is obtained from hydraulic energy____________
a) Thermal power
b) Mechanical power
c) Solar power
d) Hydroelectric power
Explanation: Hydroelectric power is generated by using hydraulic machines. Potential energy of water is converted to mechanical energy which is connected to dynamo to generate electrical energy.

23. At present which is cheapest means of generating power_____________
a) Thermal power
b) Nuclear power
c) Hydroelectric power
d) Electric Power
Explanation: Hydraulic energy is renewable source of energy in which Potential energy of water is converted to mechanical energy which is connected to dynamo to generate electrical energy.

24. Pipes of largest diameter which carry water from reservoir to the turbines is known as_____________
b) Tail race
c) Tail stock
d) Pen stock
Explanation: Penstocks are channels which transport water from reservoir to turbines which are usually made up of cast iron or concrete.

25. Pen stocks are made up of_____________
a) Steel
b) Cast iron
c) Mild steel
d) Wrought iron
Explanation: Penstocks are channels which transport water from reservoir to turbines which are usually made up of cast iron or concrete.

26. ____________is an inward radial flow reaction turbine?
a) Pelton turbine
b) Kaplan turbine
c) Francis turbine
d) Propeller turbine
Explanation: Kaplan and propeller are outward axial flow reaction turbines but Francis is outward radial flow reaction turbine.

27. The important type of axial flow reaction turbines are ______________
a) Propeller and Pelton turbines
b) Kaplan and Francis turbines
c) Propeller and Francis turbines
d) Propeller and Kaplan turbines
Explanation: Axial flow turbine is a turbine in which water flows axially outwards and turbines fall into this category are propeller and Kaplan turbines.

28. ______________ is a axial flow reaction turbines, if vanes are fixed to hub of turbine
a) Propeller turbine
b) Francis turbine
c) Kaplan turbine
d) Pelton turbine
Explanation: Axial flow turbine is a turbine in which water flows axially outwards, if vanes are fixed to hub of turbine it is known as Propeller turbine but if vanes are free to move it is known as Kaplan Turbine.

29. Francis and Kaplan turbines are known as _______
a) Impulse turbine
b) Reaction turbine
c) Axial flow turbine
d) Mixed flow turbine
Explanation: Francis and Kaplan are reaction turbines because pressure energy of water changes when it enters the rotor.

30. Specific speed of reaction turbine is between?
a) 5 and 50
b) 10 and 100
c) 100 and 150
d) 150 and 300
Explanation: Specific turbines of reaction turbines such as Francis and Kaplan lie under the range 10-100.

31. _____________ is defined as ratio between power delivered to runner and power supplied at inlet of turbine.
a) Mechanical efficiency
b) Volumetric efficiency
c) Hydraulic efficiency
d) Overall efficiency
Explanation: Hydraulic efficiency is defined as ratio between power given by water to runner of turbine and to the power supplied by water at inlet of the turbine.

32. Which among the following which is not an efficiency of turbine?
a) Mechanical efficiency
b) Volumetric efficiency
c) Hydraulic efficiency
d) Electrical efficiency
Explanation: Electrical efficiency is ratio of work output and electrical power input to electrical machine but turbine is a hydraulic machine which consists of only mechanical, volumetric and hydraulic efficiencies.

33. The ratio of power at the shaft of turbine and power delivered by water to runner is known as?
a) Mechanical efficiency
b) Volumetric efficiency
c) Hydraulic efficiency
d) Overall efficiency
Explanation: Due to mechanical losses, power available at shaft of turbine is less than power delivered to the runner of turbine. Hence ratio of power at the shaft of turbine and power delivered by water to runner is known as mechanical efficiency.

34. The product of mechanical efficiency and hydraulic efficiency is known as?
a) Mechanical efficiency
b) Volumetric efficiency
c) Hydraulic efficiency
d) Overall efficiency
Explanation: Overall efficiency is defined as ratio of power available at shaft of turbine to power supplied at the inlet of turbine which is also product of mechanical and hydraulic efficiency.

35. Among the following which turbine has highest efficiency?
a) Kaplan turbine
b) Francis turbine
c) Pelton turbine
d) Propeller turbine
Explanation: Kaplan is inward flow reaction turbine and is operated under head less than 60 meters. The vanes attached to hub are adjustable and Kaplan is mainly operated in location where large quantity of water at low head is available.

36. _____________ is ratio of volume of water actually striking the runner and volume of water supplied to turbine?
a) Mechanical efficiency
b) Volumetric efficiency
c) Hydraulic efficiency
d) Overall efficiency
Explanation: Volumetric efficiency is ratio between volume of water actually striking the runner of turbine and volume of water supplied to the turbine.

37. In the expression for overall efficiency of turbine, which is p/(k*g*q*h), where “k” is known as
a) Density of liquid
b) Specific density of liquid
c) Volume of liquid
d) Specific gravity of liquid
Explanation: Overall efficiency is defined as ratio of power available at shaft of turbine to power supplied at the inlet of turbine which is also product of mechanical and hydraulic efficiency. Its expression is given by p/(k*g*q*h) where k is density of liquid.

38. The expression for maximum hydraulic efficiency of pelton turbine is given by?
a) (1+cos k)/2 where k is outlet blade angle
b) (2+cos k)/2 where k is outlet blade angle
c) (3+cos k)/2 where k is outlet blade angle
d) (4+cos k)/2 where k is outlet blade angle
Explanation: Hydraulic efficiency is defined as ratio between power given by water to runner of turbine and to the power supplied by water at inlet of the turbine. Its maximum value is obtained by replacing u=v/2 and it is (1+cos k)/2 where k is outlet blade angle.

39. To obtain maximum hydraulic efficiency of pelton turbine, blade velocity should be ___________ Times the inlet velocity of jet.
a) Half
b) One quarter
c) Twice
d) Thrice
Explanation: Hydraulic efficiency is defined as ratio between power given by water to runner of turbine and to the power supplied by water at inlet of the turbine. This efficiency will be maximum when differentiating it with “u” and it is obtained as u=v/2.

40. Among the following which turbine has least efficiency?
a) Pelton turbine
b) Kaplan turbine
c) Francis turbine
d) Propeller turbine
Explanation: Pelton turbine is an impulse turbine, where there is no theoretical limit for head due to high head there is loss due to friction when water passing through penstocks hence its efficiency is less.

41. Velocity triangles are used to analyze ____________
a) Flow of water along blades of turbine
b) Measure discharge of flow
c) Angle of deflection of jet
d) Flow of water, measure of discharge, angle of deflection.
Explanation: By using velocity triangles we can determine discharge of flow, angle of deflection of jet and to measure relative velocity of jet with respect to speed of wheel.

42. In which of following turbine inlet and outlet blade velocities of vanes are equal?
a) Francis turbine
b) Kaplan turbine
c) Pelton turbine
d) Propeller turbine
Explanation: In Pelton turbine each blade has same angular velocity and same linear speed unlike Francis and Kaplan turbines.

43. Tangential velocity of blade of Pelton wheel is proportional to ____________
a) Speed of wheel
b) Angular velocity of wheel
c) Rpm of wheel
d) Speed, angular velocity, RPM of the wheel
Explanation: Usually velocity of blade is given by u=radius*angular velocity from which velocity is proportional to speed of wheel.

44. The value of coefficient of velocity is _____________
a) 0.98
b) 0.65
c) 0.85
d) 0.33
Explanation: Coefficient of velocity is defined as ratio of actual velocity of jet at vena contraction to theoretical velocity. Its value is approximate to 0.98.

45. In which of following turbine inlet whirl velocity and inlet jet velocity are equal in magnitude?
a) Pelton turbine
b) Propeller turbine
c) Kaplan turbine
d) Francis turbine
Explanation: In Pelton turbine velocity of inlet is parallel to splitter and is parallel to x axis which doesn’t have flow velocity.

46. In Pelton wheel, if outlet velocity angle of jet is “acute angled” then outlet whirl velocity of jet is ______________
a) x- component of V(r2) – blade velocity
b) x- component of V (r2) + blade velocity
c) Blade velocity – x- component of V (r2)
d) Zero
Explanation: By constructing velocity triangle we come to know that whirl velocity of jet is equal in magnitude to that of x- component of V r2 – blade velocity.

47. In Pelton wheel, if outlet velocity angle of jet is “obtuseangled” then outlet whirl velocity of jet is _____________
a) x- component of V (r2) – blade velocity
b) x- component of V (r2) + blade velocity
c) Blade velocity – x- component of V (r2)
d) Zero
Explanation:By constructing velocity triangle we come to know that whirl velocity of jet is equal in magnitude to that of Blade velocity – x- component of V (r2).

48. In Pelton wheel, if outlet velocity angle of jet is “right angled” then outlet whirl velocity of jet is __________
a) x- component of V (r2) – blade velocity
b) x- component of V (r2) + blade velocity
c) Blade velocity – x- component of V (r2)
d) Zero
Explanation: By constructing velocity triangle we come to know that whirl velocity of jet is equal to zero as x- component of V(r2)= blade velocity.

49. In Pelton wheel, relative inlet velocity of jet with respect to velocity of vane is _____________
a) Difference between inlet jet velocity and blade velocity
b) Sum of inlet jet velocity and blade velocity
c) Inlet jet velocity
Explanation: In Pelton turbine, inlet velocity of jet and velocity of vanes are in same direction and of different magnitude hence relative velocity is found by calculating its difference.

50. In Pelton wheel if angle of deflection is not mentioned then we assume it as______________
a) 150 degrees
b) 200 degrees
c) 165 degrees
d) 185 degrees
Explanation: It is standard value for deflection of jet, which is found by performing several experimental operations.

51. The work done per unit weight of water jet striking runner blades of Pelton turbine is given by expression ______________
a) [Vw1+Vw2] u/g
b) Vw1*u/g
c) [Vw1+Vw2]/g
d) [Vw1+Vw2]u
Explanation: Generally work done is force times velocity and expression for it is PQ [Vw1+Vw2] u/g and work done per unit weight gives [Vw1+Vw2]u/g.

52. In Pelton turbine the energy available at inlet of runner that is at outlet of nozzle is known as
a) Shaft power
b) Runner power
c) Output power
d) Water power
Explanation: In Pelton turbine the energy available at inlet of runner that is at outlet of nozzle is known as runner power, the energy available in penstock is water energy.

53. In Pelton turbines the expression for power delivered at inlet to runner is given by __________
a) W*[Vw1+Vw2]u/g
b) W*[Vw1-Vw2]u/g
c) W*[Vw1+Vw2]u/g, W*[Vw1-Vw2]u/g
d) [Vw1+Vw2]u/g
Explanation: Generally work done is force times velocity and expression for it is PQ [Vw1+Vw2] u/g and work done per unit weight gives [Vw1+Vw2]u/g.

54. In Pelton turbine runner power is more when compared with power available at exit of nozzle.
a) True
b) False
Explanation: Runner power is less when compared with power available at exit of nozzle due to frictional losses.

5. Kinetic energy of jet at inlet of turbine is given as __________________
a) 0.5(paV1)*V1
b) 0.5(paV1)*V1*V1
c) 0.5(aV1)*V1*V1
d) 0.5(pV1)*V1*V1
p= density of liquid, a= area of jet, V1= inlet jet velocity
Explanation: Expression for kinetic energy is product of half times mass and square of velocity, mass can be written as density time volume.

56. The force exerted by a jet of water in the direction of jet of jet on a stationary curved plates Fx is ____________
a) pav*v
b) pav
c) pav*v(1+cos k)
d) pav*v(1+sin k)
p=density, v= velocity of jet, k= blade angle
Explanation: Generally force is rate of change of momentum, in curved blade of angle k change of momentum will be pav*v (1+cos k).

57. The force exerted by a jet of water in the direction of jet of jet on moving curved plates is ___________
a) pa(v-u)*(v-u)
b) pa(v-u)
c) pav*(v-u)(1+cos k)
d) pa(v-u)*(v-u)(1+sin k)
p=density, v= velocity of jet, k= blade angle, u= blade velocity
Explanation: Generally force is rate of change of momentum, in curved blade of angle k change of momentum will bepav*(v-u)(1+cos k) here relative velocity is considered than absolute.

58. Calculate work done by jet per second on the runner where, discharge=0.7cubic meters/s, inlet and outlet whirl velocities be 23.77 and 2.94?
a) 200Kw
b) 150Kw
c) 187Kw
d) 250Kw
Explanation: As we know the expression for work done per second is W*[Vw1+Vw2] u/g on substituting the above given values we get it as 187Kw.

59. The power supplied at inlet of turbine in S.I units is known as_____________
a) Shaft power
d) Runner power
c) Water power
d) Total power
Explanation: The power supplied at inlet of turbine in S.I units is known as water energy, which contain both kinetic energy and pressure energy.

60.The expression for water power in Pelton wheel is ________________
a) (P*g*Q*H) Kw
b) (g*Q*H*a) Kw
c) (g*Q) Kw
d) (g*H) Kw
Explanation: Expression for water power of Pelton turbine is potential energy of water which is converted into kinetic energy
can be written as (P*g*Q*H) Kw.

61. The hydraulic efficiency of Pelton turbine will be maximum when blade velocity is equal to _______
a) V/2
b) V/3
c) V/4
d) V/5
Explanation: Hydraulic efficiency is defined as ratio between power given by water to runner of turbine and to the power supplied by water at inlet of the turbine. This efficiency will be maximum when differentiating it with “u” and it is obtained as u=v/2.

62. In Pelton turbine ___________ is defined as ratio between power delivered to runner and power supplied at inlet of turbine
a) Mechanical efficiency
b) Volumetric efficiency
c) Hydraulic efficiency
d) Overall efficiency
Explanation: Hydraulic efficiency is defined as ratio between power given by water to runner of turbine and to the power supplied by water at inlet of the turbine.

63. The maximum efficiency of Pelton turbine is _________
a) 80%
b) 70%
c) 50%
d) 88%
Explanation: We know that efficiency will be Maximumwhen blade velocity is equal to half of its jet velocity upon substitution we get efficiency as 50%.

64. In Pelton turbine product of mechanical efficiency and hydraulic efficiency is known as _____________
a) Mechanical efficiency
b) Volumetric efficiency
c) Hydraulic efficiency
d) Overall efficiency
Explanation: Overall efficiency is defined as ratio of power available at shaft of turbine to power supplied at the inlet of turbine which is also product of mechanical and hydraulic efficiency.

65. Among the following which turbine has least efficiency?
a) Pelton turbine
b) Kaplan turbine
c) Francis turbine
d) Propeller turbine
Explanation: Pelton is impulse turbine and remaining are reaction turbine, efficiency of reaction turbine is more compared to impulse turbine.

66. In Pelton ____________ is ratio of volume of water actually striking the runner and volume of water supplied to turbine?
a) Mechanical efficiency
b) Volumetric efficiency
c) Hydraulic efficiency
d) Overall efficiency
Explanation: Volumetric efficiency is ratio between volume of water actually striking the runner of turbine and volume of water supplied to the turbine.

67. In Pelton turbine the ratio of volume available at shaft of turbine and power supplied at the inlet of the turbine is _______
a) Mechanical efficiency
b) Volumetric efficiency
c) Hydraulic efficiency
d) Overall efficiency
Explanation: Overall efficiency is defined as ratio of power available at shaft of turbine to power supplied at the inlet of turbine which is also product of mechanical and hydraulic efficiency.

68. The expression for maximum hydraulic efficiency of Pelto turbine is given by ______________
a) (1+cos k)/2 where k is outlet blade angle
b) (2+cos k)/2 where k is outlet blade angle
c) (3+cos k)/2 where k is outlet blade angle
d) (4+cos k)/2 where k is outlet blade angle
Explanation: Hydraulic efficiency is defined as ratio between power given by water to runner of turbine and to the power supplied by water at inlet of the turbine. Its maximum value is obtained by replacing u=v/2 and it is (1+cos k)/2 where k is outlet blade angle.

69. In the expression for overall efficiency of turbine, which is p/ (k*g*q*h), where “k” is known as _______
a) Specific density of liquid
b) Density of liquid
c) Specific gravity of liquid
d) Volume of liquid
Explanation: Overall efficiency is defined as ratio of power available at shaft of turbine to power supplied at the inlet of turbine which is also product of mechanical and hydraulic efficiency. Its expression is given by p/ (k*g*q*h) where k is density of liquid.

70. In Pelton turbine hydraulic efficiency is product of mechanical efficiency and overall efficiency.
a) True
b) False
Explanation: The above statement is false generally overall efficiency is product of mechanical and hydraulic efficiency.

71. Radial flow reaction turbines are those turbines in which water flows ____________
b) Axial direction
c) Tangential direction
d) All of the mentioned
Explanation: The name itself indicates the type of flow that is radial direction but the thing that is unknown is whether it is radially inward or outwards.

72. Main parts of radial flow reaction turbines are ______________
a) Casing
b) Guide mechanism
c) Draft tube
d) All of the mentioned
Explanation: The main parts in a radial turbine are tight casing to prevent spill of water, runner, guide vanes, guide mechanism to regulate flow and draft to increase inlet pressure.

73. Discharge through radial flow reaction turbine is ______________
a) P1*b1*Vf1
b) P2*b2*Vf2
c) P1*b2*Vf2
d) Both P1*b1*Vf1 & P2*b2*Vf2
Where, P1= perimeter of runner at inlet, P2= perimeter of runner at outlet, b= thickness and Vf= flow velocity
Explanation: Discharge of radial flow reaction turbine is product of perimeter of runner, thickness, whirl velocity, at inlet as well as outlet runner vanes.

74. Radial flow reaction turbines contain spiral casing which area ____________
a) Remains constant
d) Suddenly decreases
Explanation: Area of spiral structure gradually decreases because as discharge decreases correspondingly area also decreases. So, runner will rotate with constant velocity.

75. ____________ consists of stationary circular wheel all around the runner of turbine
a) Casing
b) Guide mechanism
c) Runner
d) Drafting
Explanation: Guide vanes are placed around the runner to regulate the flow and to provide shock less entry at inlet to runner.

76. The casing of radial flow reaction turbine is made of spiral shape, so that water may enter the runner__________
a) Variable acceleration
b) Constant acceleration
c) Variable velocity
d) Constant velocit
Explanation: Area of spiral structure gradually decreases because as discharge decreases correspondingly area also decreases. So, runner will rotate with constant velocity.

77. _____________ allow the water to strike the vanes fixed on runner without shock at inlet
a) Casing
b) Guide vanes
c) Runner
d) Draft tube
Explanation: Guide vanes are placed around the runner to regulate the flow and to provide shock less entry at inlet to runner.

78. Runner blades are made up of _____________
a) Cast steel
b) Cast iron
c) Wrought iron
d) Steel
Explanation: Runner blades are made up of cast steel because they are less corrosive and highly durable.

79. The pressure at the exit of runner of reaction turbine is generally____________than atmospheric pressure
a) Greater
b) Lesser
c) Constant
d) Equal
Explanation: In general, the exit of runner has a low pressure compared to the atmospheric pressure.

80. ___________is a pipe of gradually increasing area used for discharging water from exit of the turbine to the tail race
a) Casing
b) Guide mechanism
c) Draft tube
d) Runner
Explanation: Draft is a pipe of gradually increasing area, as water leaving runner has less pressure, draft tube will increase pressure energy of water by decreasing its velocity.

81. Inward radial flow reaction turbine is a turbine in which water flows across the blades of runner______________
d) Axial direction
Explanation: The name itself indicates that flow is in radial direction and flowing from outer periphery towards center.

82. Which of following is inward radial flow reaction turbine?
a) Pelton wheel
b) Francis turbine
c) Axial turbine
d) Kaplan turbine
Explanation: Pelton is impulse a turbine, Kaplan is axial flow turbine and Francis is an inward flow reaction turbine.

83. In Inward radial flow reaction turbine which is not required?
a) Runner
b) Air tight casing
c) Guide vanes
d) Breaking jet
Explanation: Here in inward flow reaction turbine, instead of jet water is passed into spiral casing directly and breaking jet is not used for its halt instead of it guide vanes are used.

84. The main difference between reaction turbine and inward radial flow reaction turbine is water flows___________
d) Axial direction
Explanation: The name itself indicates the type of flow that is radial direction but the thing that is unknown is whether it is radially inward or outwards.

85. In Inward radial flow reaction turbine the ratio of tangential wheel at inlet to given velocity of jet is known as _______
a) Speed ratio
b) Flow ratio
c) Discharge
Explanation: Flow ratio is known as ratio of tangential wheel at inlet to given velocity of jet and it is scalar quantity.

86. In Inward radial flow reaction turbine the ratio of tangential velocity at inlet to the given velocity ____________
a) Speed ratio
b) Flow ratio
c) Discharge
Explanation: Speed ratio is ratio of tangential velocity at inlet to the given velocity and it is scalar quantity because it is ratio of two speeds.

87. The discharge through a reaction radial flow turbine is given by____________
a) P1*b1*Vf1
b) P2*b2*Vf2
c) P1*b2*Vf2
d) Both a & b
Where, P1= perimeter of runner at inlet, P2= perimeter of runner at outlet, b= thickness and V f= flow velocity
Explanation: Discharge of radial flow reaction turbine is product of perimeter of runner, thickness, whirl velocity, at inlet as well as outlet runner vanes.

88. In Inward radial flow reaction turbine if thickness is considered then discharge is _________
a) (P1-n*t)*b1*Vf1
b) (P2-n*t)*b2*Vf2
c) (P1-n*t)*b2*Vf2
d) Both a & b
Where, P1= perimeter of runner at inlet, P2= perimeter of runner at outlet, b= width, Vf= flow velocity, n= number of blades and t= thickness of blades
Explanation: Discharge of radial flow reaction turbine is product of perimeter of runner, thickness, whirl velocity, at inlet as well as outlet runner vanes. If n blades of thickness t is considered then discharge is (P1-n*t)*b1*Vf1.

89. In Inward radial flow reaction turbine if angle made by absolute velocity with its tangent is 90 degrees and component of whirl is zero at outlet is _____________
a) Radial inlet discharge
b) Radial outlet discharge
c) Flow ratio
d) Speed ratio
Explanation: If angle made by absolute velocity with its tangent is 90 degrees and component of whirl is zero at outlet in radial flow reaction then total velocity will be flow velocity.

90. In which of following turbine whirl component is zero?
a) Reaction turbine
b) Inward radial flow reaction turbine
c) Axial flow turbine
d) Impulse turbine
Explanation: If angle made by absolute velocity with its tangent is 90 degrees and component of whirl is zero at outlet in radial flow reaction turbines then total velocity will be flow velocity.

91. In an outward flow reaction turbine, water from casing enters guiding wheel.
a) True
b) False
Explanation: Water enters the stationary guide wheel from the casing of the turbine in the outward radial flow reaction turbine.

92. The water from penstocks enters the _____ which is spiral in shape which the area of cross section of casing goes on decreasing gradually
a) guide wheel
b) draft tube
c) casing
d) runner
Explanation: The water from penstocks enters the casing which is spiral in shape in which the area of cross section of casing decreases gradually.

93. If the water flows from inwards to outwards, the turbine is known as _____________
a) Tangential flow turbine
b) Turbulent low inward flow
c) Inward flow turbine
d) Outward flow turbine
Explanation: If the water in the runner flows from inwards to outwards, then such type of turbine is said to be outward radial flow turbine.

84. In general, reaction turbines consist of which types of energies?
a) kinetic energy and potential energy
b) potential energy and pressure energy
c) kinetic energy and pressure energy
d) gravitational energy and potential energy
Explanation: Reaction turbine is a kind of turbine in which the water at inlet of the turbine possesses both kinetic energy and pressure energy.

85. ___________ is a circular wheel on which a series of smooth, radial curved vanes are fixed.
a) Guide wheel
b) Runner
c) Casing
d) Draft tube
Explanation: The radial curved vanes are so shaped that water enters and leaves the runner without shock .It is a circular type wheel on which a series of smooth, radial curved vanes are fixed.

86. In outward radial flow reaction turbines, tangential velocity at inlet is less than that of the outlet.
a) False
b) True
Explanation: In outward radial flow reaction turbines, tangential velocity at inlet is less than that of the outlet as the inlet of the runner is the inner diameter.

87. In an outward radial flow reaction turbine the ratio of tangential wheel at inlet to given velocity of jet is known as ___________
a) Speed ratio
b) Flow ratio
c) Discharge
Explanation: Flow ratio is known as ratio of tangential wheel at inlet to given velocity of jet and it is scalar quantity.

98. In an outward radial flow reaction turbine the ratio of tangential velocity at inlet to the given velocity is ______
a) Speed ratio
b) Flow ratio
c) Discharge
Explanation: Speed ratio is ratio of tangential velocity at inlet to the given velocity and it is scalar quantity because it is ratio of two speeds.

99. Discharge in an outward flow reaction turbine ____________
a) Increases
b) Decreases
c) Remains constant
Explanation: Discharge in an outward flow reaction turbine increases because area increases as fluid flows across spiral structure in the turbine.

100. An outward radial reaction turbine has ______
a) u1 < u2
b) u1 > u2
c) u1 = u2
d) u2 = u1 = 0
Explanation: For an outward flow reaction turbine, tangential velocity at inlet should be less than the tangential velocity at outlet.

#### Module 06

1. Centrifugal pump is a_________
a) Turbomachinery
b) Flow regulating device
c) Drafting device
d) Intercooling device
Explanation: Centrifugal pump is a turbomachinery. Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbines and compressors. It is a mechanical device.

2. Turbomachines work under ________
a) Newtons first law
b) Newtons second law
c) Newtons third law
d) Kepler’s law
Explanation: Turbomachines work under Newtons second law. Centrifugal pump is a turbomachinery. Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbines and compressors. It is a mechanical device.

3. The main function of nozzle is to __________
a) Varying temperatures
b) Pressure variations
d) Heat variations
Explanation: The main function of nozzle is to vary the pressure of fluid passing through the nozzle. It is done by opening and shutting the sets of nozzles. Thus, its main function is to regulate pressure of the fluid.

4. The main function of centrifugal pumps are to ________
a) Transfer speed
b) Transfer pressure
c) Transfer temperature
d) Transfer energy
Explanation: The primary objective of a centrifugal pump is to transfer energy. Centrifugal pump is a turbomachinery. Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbines and compressors. It is a mechanical device.

5. Centrifugal pumps transfer energy from _______
a) Rotor to fluid
b) Fluid to rotor
c) Draft to rotor
d) Rotor to draft
Explanation: Centrifugal pumps transfer energy from rotor to fluid. The primary objective of a centrifugal pump is to transfer energy. Centrifugal pump is a turbomachinery.

6. Which among the following control the flow rate?
a) Valve
b) Pump
d) Tank pipe
Explanation: Flow rate of the tank is controlled by the valve. The actuation of individual valve closes. This corresponds to the set of nozzle thereby controlling the actual flow rate of the fluid passing through the valve.

7. Turbines and compressors work with the gas, while centrifugal pump transfers energy.
a) True
b) False
Explanation: Turbines and compressors work with the gas, while centrifugal pump transfers energy. Centrifugal pumps transfer energy from rotor to fluid. The primary objective of a centrifugal pump is to transfer energy. Centrifugal pump is a turbomachinery.

8. The inlet passage of water entry is controlled by ________
b) Gate
c) Tail race
d) Pump
Explanation: The inlet passage of water entry is controlled by the gate opening. The gate opening is an opening that sends only a percentage of fluid through the inlet passages for water to enter to the turbine.

9. Centrifugal pumps are a sub class of dynamic axisymmetric work absorbing turbomachinery.
a) True
b) False
Explanation: The statement is true. Centrifugal pumps are a sub class of dynamic axisymmetric work absorbing turbomachinery. The main function of centrifugal pumps are to transfer energy.

10. Centrifugal pumps are used to transport ________
a) Pressure
b) Speed
c) Power
d) Fluid
Explanation: Centrifugal pumps are used to transport fluids. They transport fluids by conversion of energies. Centrifugal pumps are a sub class of dynamic axisymmetric work absorbing turbomachinery.

11. A gear pump uses ___________
a) Petrochemical pumps
b) Meshing of gears
c) Froth pumps
d) Airlift pumps
Explanation: A gear pump uses meshing of gears. This meshing is done to pump fluid by displacement. Gear pumps are widely used in chemical installations.

12. The fundamental significance of all the turbomachinery is _______
a) Conservation of momentum
b) Conservation of mass
c) Conservation of heat
d) Conservation of speed
Explanation: The fundamental significance of all the turbomachinery is the conservation of momentum. It plays an important role in various turbomachinery.

13. The most common pump used for hydraulic fluid power application is __________
a) Centrifugal pumps
b) Gear pump
c) Froth pumps
d) Airlift pumps
Explanation: The most common pump used for hydraulic fluid power application is gear pump. A gear pump uses meshing of gears. This meshing is done to pump fluid by displacement. Gear pumps are widely used in chemical installations.

14. The change of angular momentum in a pump is equal to the _________
a) Sum of speeds
b) Sum of individual momentum
c) Sum of temperatures
d) Sum of energy transferred from a body
Explanation: The change of angular momentum in a pump is equal to the sum of individual momentum.

15. Conservation of angular momentum is described by _______
a) Newtons equation
b) Euler’s equation
c) Rutherford’s equation
d) Maxim equation
Explanation: Conservation of angular momentum is described by Euler’s equation. It states that the change of angular momentum in a pump is equal to the sum of individual momentum.

16. Gear pumps are mainly used in chemical installations because they pump ________
a) High viscosity fluids
b) High density fluids
c) High pressure fluids
d) High temperature fluids
Explanation: Gear pumps are mainly used in chemical installations because they pump high viscosity fluids. They use two external spur gears for this purpose.

17. Gear pumps convert rotational kinetic energy to hydrodynamic energy.
a) True
b) False
Explanation: Gear pumps are used to transport fluids. They transport fluids by conversion of energies. Gear pumps transport fluids by converting rotational Kinetic energy to hydrodynamic energy.

18. The inlet passage of centrifugal pump is controlled by ________
a) Gate
c) Turbine
d) Pump
Explanation: The inlet passage of water entry is controlled by the gate opening. The gate opening is an opening that sends only a percentage of fluid through the inlet passages for water to enter to the turbine.

19. Absolute exit velocity in a pump is denoted as ______
a) c2
b) v2
c) p2
d) w2
Explanation: Absolute exit velocity in a pump is denoted as ‘c2’.

20. Gear pumps are used to transport ________
a) Pressure
b) Speed
c) Power
d) Fluid
Explanation: Gear pumps are used to transport fluids. They transport fluids by conversion of energies. A gear pump uses meshing of gears. This meshing is done to pump fluid by displacement. Gear pumps are widely used in chemical installations.

21. The fluid gains _________ while passing through the impeller.
a) Velocity
b) Pressure
c) Temperature
d) Velocity and pressure
Explanation: The fluid gains both velocity and pressure while passing through the impeller. Centrifugal pump is a turbomachinery. Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbines and compressors.

22. What is the shape of the diffuser in the centrifugal pump?
a) Round
b) Dough nut
c) Rectangle
d) Cylindrical
Explanation: The shape of the diffuser passing present in the centrifugal pump is doughnut shaped. It is made into that shape as it allows the device to scroll up and down. Due to this, the casing decelerates the flow.

23. When the casing in a centrifugal pump decelerates the flow, what increases?
a) Pressure
b) Temperature
c) Volume
d) Flow rate
Explanation: When the casing in a centrifugal pump decelerates the flow, pressure in the turbine increases. The diffuser helps this happen. The shape of the diffuser passing present in the centrifugal pump is doughnut shaped.

24. The velocity imparted by the impeller is converted into _________
a) Pressure energy
b) Kinetic energy
c) Momentum
d) Potential energy
Explanation: The velocity imparted by the impeller is converted into pressure energy. It is in accordance with the Newtons second law.

25. The consequence of Newtons second law is_________
a) Conservation of angular momentum
b) Conservation of mass
c) Conservation of potential energy
d) Conservation of kinetic energy
Explanation: The consequence of Newtons second law is the conservation of angular momentum. This, in accordance with newtons second law, provides the basic details to define parameters in the centrifugal pump.

26. Change of angular momentum is equal to ________
a) Sum of external moments
b) Sum of their potential energies
c) Sum of their kinetic energies
d) Sum of their pressures
Explanation: Change of angular momentum is equal to Sum of external moments. This is in accordance with Newtons second law. The consequence of Newtons second law is the conservation of angular momentum.

27. Euler developed the head pressure equation in centrifugal pumps.
a) True
b) False
Explanation: Centrifugal pumps are used to transport fluids. They transport fluids by conversion of energies. Centrifugal pumps transport fluids by converting rotational Kinetic energy to hydrodynamic energy. Euler developed the head pressure equation in centrifugal pumps.

28. What is a major advantage of centrifugal pump?
a) Cost
b) Simple in construction
c) Efficiency
d) Pump parameters
Explanation: The major advantage of the centrifugal pump is that it has got a simple construction when compared to other types of centrifugal pumps.

29. ‘Ht’ means _______
c) Theory head pressure
Explanation: ‘Ht’ in the context of centrifugal pump means theory head pressure. It is used in a centrifugal pump equation that was derived by Euler. Euler developed the head pressure equation in centrifugal pumps.

30. Centrifugal pumps are used to transport ________
a) Pressure
b) Speed
c) Power
d) Fluid
Explanation: Centrifugal pumps are used to transport fluids. They transport fluids by conversion of energies. Centrifugal pumps are a sub class of dynamic axisymmetric work absorbing turbomachinery.

31. What is the unit of flow rate?
a) kg.m
b) kg/m
c) m3/s
d) /s
Explanation: The unit of flow rate in a centrifugal pump is m3/s. It is denoted as ‘Q’. It plays an important role to determine the efficiency of the pump.

32. With the increase in the flow rate, efficiency ______
a) Decreases
b) Increases
c) Remains same
d) Independent
Explanation: With the increase in the flow rate, efficiency increases. The unit of flow rate in a centrifugal pump is m3/s. It is denoted as ‘Q’. It plays an important role to determine the efficiency of the pump.

33. Pump efficiency is defined as the ratio of ___________
a) Pressure to temperature
b) Temperature to pressure
c) Water horsepower to pump horsepower
d) Pump horse power to water horse power
Explanation: Pump efficiency is defined as the ratio of water horsepower to the pump horsepower. The unit of flow rate in a centrifugal pump is m3/s. It is denoted as ‘Q’. It plays an important role to determine the efficiency of the pump.

34. The difference in the total head of the pump is called _______
Explanation: The difference in the total head of the pump is called manometric head. Centrifugal pump is a turbomachinery. Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbines and compressors.

35. The ratio of manometric head to the work head is called _______
Explanation: The ratio of manometric head to the work head is called Euler head. It is also called as manometric efficiency.

36. What is the unit of energy head?
a) m
b) m/s
c) m3/s
d) /s
Explanation: The unit of energy head is meter. The energy head is denoted as ‘H’. It plays an important role to determine the efficiency of the pump.

37. With the increase in energy head, efficiency ________
a) Decreases
b) Increases
c) Remains same
d) Independent
Explanation: With the increase in energy head, efficiency increases. Since energy is directly proportional to the efficiency of the turbine. The unit of energy head is meter. The energy head is denoted as ‘H’. It plays an important role to determine the efficiency of the pump.

38. The head added by the pump is a sum of _________
a) Pressure
b) Static lift
c) Volume
d) Flow rate
Explanation: The head added by the pump is a sum of static lift. With the increase in energy head, efficiency increases. Since energy is directly proportional to the efficiency of the turbine. The unit of energy head is meter. The energy head is denoted as ‘H’. It plays an important role to determine the efficiency of the pump.

39. Power is most commonly expressed as ________
a) m
b) kW
c) m3/s
d) /s
Explanation: Power is most commonly expressed as kilo watts. One kilo watts is equal to 0.746 horse power. It plays an important role in determining the efficiency of the turbine.

40. PHE stands for __________
a) Pump Hydraulic efficiency
b) Pressure Hydraulic efficiency
c) Power Hydraulic efficiency
d) Pump hydraulic engine
Explanation: PHE stands for Pump hydraulic efficiency. Centrifugal pumps are used to transport fluids. They transport fluids by conversion of energies.

41. In hydraulic head, NPSH is used for the analysis of __________
b) Priming
c) Wear
d) Cavitation
Explanation: In hydraulic head, net positive circuit is used for the analysis of cavitation. It determines the cavitation present in the centrifugal pump by different methods.

42. NPSH is the difference between _______
a) Suction pressure and vapour pressure
b) Vapour pressure and suction pressure
c) Suction pressure and heat
d) Shaft and head
Explanation: NPSH is defined as the difference suction pressure and vapour pressure. It is called as the net positive suction head.

43. What can NPSH be used to determine _______
a) Friction characteristics
b) Pipe diameter
c) Cavitation
d) Thermal expansion
Explanation: NPSH is used to determine the cavitation in pumps. NPSH is defined as the difference suction pressure and vapour pressure. It is called as the net positive suction head.

44. The measure of how close the fluid is to the given point is called _________
a) Flashing
b) Darcy’s factor
c) Transfer temperature
d) Heizenberg’s factor
Explanation: The measure of how close the fluid is to the given point is called flashing. It is one of the major methods in the NPSH to determine the cavitation.

45. What is the dimension for Darcy’s friction factor?
a) kg/m
b) N/mm
c) kg
d) Dimensionless
Explanation: Darcy’s friction factor is dimensionless. It is one of the major applications in Fluid dynamics. The energy usage in pumping installation is determined by Friction characteristics. Thus, it is dimensionless.

46. NPSH is relevant ________
a) Outside the pumps
b) Inside the pumps
c) Away from the pumps
d) Series and parallel with the pumps
Explanation: NPSH is relevant inside the pumps. hydraulic head, net positive circuit is used for the analysis of cavitation. It determines the cavitation present in the centrifugal pump by different methods.

47. With the increase in cavitation, the drag coefficient of the impeller ______
a) Increases
b) Decreases
c) Same
d) Independent
Explanation: With the increase in cavitation, the drag coefficient of the impeller increases. When the flow output is higher, impellers are connected in parallel. The impeller is mounted on one shaft or different shaft.

48. What is the full form of NPSH in a pump?
a) Net pressure suction head
b) Net positive suction head
c) Non-pressure suction head
d) Net pressure super head
Explanation: The full form of NPSH is Net positive suction head. The head added by the pump is a sum of static lift. Thus, corresponds to the efficient working of the pump. Higher the NPSH, more efficient the pump is.

49. When the NPSH is low, it leads to ________
a) Breaking
b) Wear
c) Corrosion
d) Cavitation
Explanation: When the NPSH is low, it leads to cavitation. Cavitation is one of the major drawbacks that are seen in a centrifugal pump. There are various other problems as well. But, cavitation is due to low NPSH.

50. What is positive suction head?
a) Draft tube is above
b) Pump pressure is above
c) Liquid level is above
d) Turbine head is above
Explanation: Positive suction head is defined as the point in which the liquid level is above the centre line of the pump.

51. When a pump casing is filled with liquid before it is started, it is called as _________
b) Priming
d) Isentropic expansion
Explanation: When a pump casing is filled with liquid before it is started, it is called as priming. Most of the centrifugal pumps are not self priming. At this stage, the pump will not be able to function.

52. The pump will become incapable of pumping in case of _______
a) Gas bounding
b) Throttle bush
c) Stuffing box
d) Casing breakage
Explanation: For an oil field to have solid control, it needs centrifugal pumps. At each stage in the centrifugal pump, the fluid is directed to towards the centre. This makes it more efficient in operating a large oil field.

53. Priming is needed when impeller cannot impart enough _________
a) Draft speed
b) Energy
c) Pressure
d) Heat
Explanation: Priming is needed when impeller cannot impart enough energy. Therefore priming is compulsory in this case.

54. Priming performs response using ________
a) Stimulus
b) Froth
c) Slurry
d) Heat
Explanation: Priming performs response using a stimulus. It is an implicit method in which exposure to flow of fluid takes place.

55. To avoid gas bounding, the pump is _________
a) Heated
b) Elevated
c) Primed
d) Charged
Explanation: Centrifugal pumps work under the same principle, but differ in their functions. At each stage in the centrifugal pump, the fluid is directed to towards the centre. To avoid gas bounding, the pump is primed.

56. Centrifugal pumps are located ________ the level of source
a) Below
b) Above
c) Parallel with
d) Series with
Explanation: Centrifugal pumps are located below the level of source. It is located in such way because, it takes away the suction at a faster rate.

57. A pump that can evacuate air is called as _________
a) Series pumps
b) Self priming pumps
c) Froth pumps
d) Drive pumps
Explanation: A pump that can evacuate air is called as self priming pumps. In normal conditions, it is difficult for centrifugal pumps to evacuate the air from the inlet line leading to a fluid level to a different altitude.

58. What does CPO stand for?
a) Centrifugal pump operation
b) Centrifugal part operation
c) Centrifugal pump output
d) Centrifugal part output
Explanation: CPO stands for centrifugal pump operation. It has got a pump start off procedure and pump shut down procedure.

59. Self priming pumps overshadow the function of __________
a) Self auxiliary device
b) Wear rate
c) Corrosion device
d) Cavitation device
Explanation: Self priming pumps overshadow the function of self auxiliary device. A pump that can evacuate air is called as self priming pumps. In normal conditions, it is difficult for centrifugal pumps to evacuate the air from the inlet line leading to a fluid level to a different altitude.

60. What is necessary for self priming to take place?
a) Draft tube
b) Pump casing
c) Suspended solenoids
Explanation: For self priming to take place, pump casing is necessary. This helps to evacuate air in normal conditions.

61. The formation of vapour cavities is called _____
a) Static pressure drop
b) Cavitation
c) Isentropic expansion
d) Emulsion
Explanation: The formation of vapour cavities is called cavitation. It is formed due to the presence of small free liquids with different zones. These zones consists of different layers of forces acting on them.

62. What is the degree of reaction denoted as?
a) D
b) R
c) r
d) d
Explanation: Degree of reaction is defined as the ratio of the static pressure drop in the rotor to the static pressure drop in the stage. It can also be defined in the same way for enthalpy in different stages. It is denoted by the letter ‘R’.

63. Voids are created due to ______
a) Reaction ratio
b) Pressure ratio
c) Liquid free layers
d) Volumetric layers
Explanation: Voids in a turbine or pump is created due to the presence of liquid free layers. It is formed due to the presence of small free liquids with different zones. These zones consists of different layers of forces acting on them.

64. Cavitation usually occurs due to the changes in ________
a) Pressure
b) Temperature
c) Volume
d) Heat
Explanation: Cavitation usually occurs due to the changes in pressure. The pressure change is so rapid that it leads to formation of liquid free layers or cavities that start to affect the overall performance.

65. Degree of reactions are most commonly used in ________
a) Turbomachinery
b) Pressure drag
c) Aerodynamics
d) Automobiles
Explanation: Degree of reaction is most commonly used in turbomachinery. Degree of reaction is defined as the ratio of the static pressure drop in the rotor to the static pressure drop in the stage. It can also be defined in the same way for enthalpy in different stages. It is denoted by the letter ‘R’.

66. At high pressure, the voids can generate ______
a) Drag force
b) Mass density
c) Shock waves
d) Flow speed
Explanation: At high pressure, the voids can generate shock waves. Cavitation usually occurs due to the changes in pressure. The pressure change is so rapid that it leads to formation of liquid free layers or cavities that start to affect the overall performance.

67. Voids that implode near metal surface develops a_______
a) Drag force
b) Cyclic stress
c) Shock waves
d) Flow speed
Explanation: Voids that implode near metal surface develops a cyclic stress. This happens mainly due to repeated implosion of voids.

68. Internal cavitation occurs due to __________
a) Drag force
b) Cyclic stress
c) Shock waves
d) Flow speed
Explanation: At high pressure, the voids can generate shock waves. Cavitation usually occurs due to the changes in pressure. The pressure change is so rapid that it leads to formation of liquid free layers or cavities that start to affect the overall performance.

69. Non- inertial cavitation is the one in which a bubble of fluid is forced to oscillate.
a) True
b) False
Explanation: Non- inertial cavitation is the one in which a bubble of fluid is forced to oscillate. It oscillates in a different size or shape due to some form of energy called the acoustic field.

70. The efficiency of the vane is given by _________
a) 1-V22/ V12
b) 1-(V22/ V12)
c) V22/ V12
d) 1- V12
Explanation: In a velocity triangle at the inlet and the outlet, the control volume is moving with a uniform velocity. Therefore, the momentum theorem of the control volume is at a steady flow. Thus, the efficiency of the vane is given by 1-(V22/ V12)

71. A multistage centrifugal pumps has more than two _______
a) Pumps
b) Impellers
c) Turbines
d) Magnetic pumps
Explanation: A multistage centrifugal pumps has more than two impellers. The multistage centrifugal is similar to the centrifugal pumps working.

72. The impeller is mounted on a ________
a) Draft tube
b) Throttle bush
c) Stuffing box
d) Shaft
Explanation: The impeller is mounted on one shaft or different shaft. A multistage centrifugal pump has more than two impellers. The multistage centrifugal is similar to the centrifugal pumps working.

73. At each stage the fluid is directed ________
a) Towards the centre
b) Away the centre
c) Towards the surface
d) Away from the centre
Explanation: At each stage in the centrifugal pump, the fluid is directed to towards the centre. A multistage centrifugal pump has more than two impellers. The multistage centrifugal is similar to the centrifugal pumps working.

74. If the cylinder is filled with fuel or air it is said to be ___________
a) 100% efficient
b) Transfer efficient
c) Nil efficient
d) Flow effective
Explanation: If the cylinder is filled with fuel or air, it is said to be 100 percent efficient. It plays a major role in regulating the flow of fluid.

75. SOH in a pump stands for_______
a) Shut Off head
b) Shut off heat
c) Shut off hybrid
d) Set off head
Explanation: SOH in a pump stands for Shut OFF head. The shut off head is located at the maximum head of the pipe.

76. At higher pressures, the impeller is connected in _______
a) Series
b) Parallel
c) Equilibrium
d) Series and parallel
Explanation: At higher pressures, the impeller is connected in series. The impeller is mounted on one shaft or different shaft. A multistage centrifugal pump has more than two impellers. The multistage centrifugal is similar to the centrifugal pumps working.

77. When the flow output is higher, impellers are connected in________
a) Series
b) Parallel
c) Equilibrium
d) Series and parallel
Explanation: When the flow output is higher, impellers are connected in parallel. The impeller is mounted on one shaft or different shaft. A multistage centrifugal pump has more than two impellers. The multistage centrifugal is similar to the centrifugal pumps working.

78. The point at which piping system controls the flow rate is called ______
a) Pressure point
b) Static lift
c) Operating point
d) Flow point
Explanation: The point at which piping system controls the flow rate is called operating point of the pump. It plays a major role in controlling the piping system before regulation.

79. What is the common application of multistage centrifugal pump?
a) Mineral industries
b) Boiler feed water pump
c) Removes ores
d) Detects oil