Quiz  /  Power Plant Engineering Objective Type Questions and Answers PDF

  • 1. 
    The modern steam turbines are

  • impulse turbines
  • reaction turbines
  • impulse-reaction turbines
  • none of the above

  • 2. 
    The commercial sources of energy are

  • solar, wind and biomass
  • fossil fuels, hydropower and nuclear energy
  • wood, animal wastes and agriculture wastes
  • none of the above

  • 3. 
    In India largest thermal power station is located at

  • Kota
  • Sarni
  • Chandrapur
  • Neyveli

  • 4. 
    The percentage O2 by Weight in atmospheric air is

  • 18%
  • 23%
  • 77%
  • 79%

  • 5. 
    The percentage 02 by volume in atmosphere air is

  • 21%
  • 23%
  • 77%
  • 79%

  • 6. 
    The proper indication of incomplete combustion is

  • high CO content in flue gases at exit
  • high CO2 content in flue gases at exit
  • high temperature of flue gases
  • the smoking exhaust from chimney

  • 7. 
    The main source of production of biogas is

  • human waste
  • wet cow dung
  • wet livestock waste
  • all above

  • 8. 
    India’s first nuclear power plant was installed at

  • Tarapore
  • Kota
  • Kalpakkam
  • none of the above

  • 9. 
    In fuel cell, the ______ energy is converted into electrical energy.

  • mechanical
  • chemical
  • heat
  • sound

  • 10. 
    Solar thermal power generation can be achieved by

  • using focusing collector or heliostates
  • using flat plate collectors
  • using a solar pond
  • any of the above system

  • 11. 
    The energy radiated by sun on a bright sunny day is approximately

  • 700 W/m2
  • 800 W/m2
  • 1 kW/m2
  • 2 kW/m2

  • 12. 
    Thorium Breeder Reactors are most suitable for India because

  • these develop more power
  • its technology is simple
  • abundance of thorium deposits are available in India
  • these can be easily designed

  • 13. 
    The overall efficiency of thermal power plant is equal to

  • Rankine cycle efficiency
  • Carnot cycle efficiency
  • Regenerative cycle efficiency
  • Boiler efficiency x turbine efficiency x generator efficiency

  • 14. 
    Rankine cycle operating on low pressure limit of p1 an 1 high pressure limit of p2

  • has higher the renal efficiency than the carnot cycle operating between same pressure limits
  • has lower the”nal efficiency than carnot cycle operating between same pressure limit?
  • has same thermal efficiency as carnot cycle operating between same pressure limits
  • may be more or less depending upon the magnitude of p1 and p2

  • 15. 
    Carnot cycle comprises of

  • two isentropic processes and two constant volume processes
  • two isentropic processes and two constant pressure processes
  • two isothermal processes and three constant pressure processes
  • none of the above

  • 16. 
    In Rankine cycle the work output from the turbine is given by

  • change of internal energy between inlet and outlet
  • change of enthaply between inlet and outlet
  • change of entropy between inlet and outlet
  • change of temperature between inlet and outlet

  • 17. 
    Regenerative cycle thermal efficiency

  • is always greater than simple Rankine thermal efficiency
  • is greater than simple Rankine cycle thermal efficiency only when steam is bled at particular pressure
  • is same as simple Rankine cycle thermal efficiency
  • is always less than simple Rankine cycle thermal efficiency

  • 18. 
    In a regenerative feed heating cycle, the optimum value of the fraction of steam extracted for feed heating

  • decreases with increase in Rankine cycle efficiency
  • increases with increase in Rankine cycle efficiency
  • is unaffected by increase in Rankine cycle efficiency
  • none of the above

  • 19. 
    In a regenerative feed heating cycle, the greatest economy is affected

  • when steam is extracted from only one suitable point of steam turbine
  • when steam is extracted from several places in different stages of steam turbine
  • when steam is extracted only from the last stage of steam turbine
  • when steam is extracted only from the first stage of steam turbine

  • 20. 
    The maximum percentage gain in Regenerative feed heating cycle thermal efficiency

  • increases with number of feed heaters increasing
  • decreases with number of feed heaters increasing
  • remains same unaffected by number of feed heaters
  • none of the above

  • 21. 
    In regenerative cycle feed water is heated by

  • exhaust gases
  • heaters
  • draining steam from the turbine
  • all above

  • 22. 
    Reheat cycle in steam power plant is used to

  • utilise heat of flue gases
  • increase thermal efficiency
  • improve condenser performance
  • reduce loss of heat

  • 23. 
    Mercury is a choice with steam in binary vapour cycle because it has

  • higher critical temperature and pressure
  • higher saturation temperature than other fluids
  • relatively low vapourisation pressure
  • all above

  • 24. 
    Economiser is used to heat

  • air
  • feed water
  • flue gases
  • all above

  • 25. 
    The draught which a chimney produces is called

  • induced draught
  • natural draught
  • forced draught
  • balanced draught

  • 26. 
    The draught produced by steel chimney as compared to that produced by brick chimney for the same height is

  • less
  • more
  • same
  • may be more or less

  • 27. 
    In a boiler installation the natural draught is produced

  • due to the fact that furnace gases being light go through the chimney giving place to cold air from outside to rush in
  • due to the fact that pressure at the grate due to cold column is higher than the pressure at the chimney base due to hot column
  • due to the fact that at the chimney top the pressure is more than its environmental pressure
  • all of the above

  • 28. 
    The draught produced, for a given height of the chimney and given mean temperature of chimney gases

  • decreases with increase in outside air temperature
  • increases with increase in outside air temperature
  • remains the same irrespective of outside air temperature
  • may increase or decrease with increase in outside air temperature

  • 29. 
    The draught produced by chimney of given height at given outside temperature

  • decreases if the chimney gas temperature increases
  • increases if the chimney gas temperature increases
  • remains same irrespective of chimney gas temperature
  • may increase or decrease

  • 30. 
    For forced draught system, the function of chimney is mainly

  • to produce draught to accelerate the combustion of fuel
  • to discharge gases high up in the atmosphere to avoid hazard
  • to reduce the temperature of the hot gases discharged
  • none of the above

  • 31. 
    Artificial draught is produced by

  • air fans
  • steam jet
  • fan or steam jet
  • all of the above

  • 32. 
    The draught in locomotive boilers is produced by

  • forced fan
  • chimney
  • steam jet
  • only motion of locomotive

  • 33. 
    For the same draught produced the power of induced draught fan as compared to forced draught fan is

  • less
  • more
  • same
  • not predictable

  • 34. 
    The artificial draught normally is designed to produce

  • less smoke
  • more draught
  • less chimney gas temperature
  • all of the above

  • 35. 
    The pressure at the furnace is minimum in case of

  • forced draught system
  • induced draught system
  • balanced draught system
  • natural draught system

  • 36. 
    The efficiency of chimney is approximately

  • 80%
  • 40%
  • 20%
  • 0.25%

  • 37. 
    The isentropic expansion of steam through nozzle for the steam initially superheated at inlet is approximated by equation

  • pvls=C
  • pv1126 = C
  • pv1A = C
  • pv = C

  • 38. 
    The ratio of exit pressure to inlet pressure of maximum mass flow rate per area of steam through a nozzle when steam is initially superheated is

  • 0.555
  • 0.578
  • 0.5457
  • 0.6

  • 39. 
    The critical pressure ratio of a convergent nozzle is defined as

  • the ratio of outlet pressure to inlet pressure of nozzle
  • the ratio of inlet pressure to outlet pressure of nozzle
  • the ratio of outlet pressure to inlet pressure only when mass flow rate per unit area is minimum
  • the ratio of outlet pressure to inlet pressure only when mass flow rate = c

  • 40. 
    The isentropic expansion of steam through nozzle for the steam initially dry saturated at inlet is approximated by equation.

  • pv = C
  • pv1A = C
  • pv1i = C
  • pv

  • 41. 
    The effect of considering friction in steam nozzles for the same pressure ratio leads to

  • increase in dryness fraction of exit steam
  • decrease in dryness fraction of exit steam
  • no change in the quality of exit steam
  • decrease or increase of dryness fraction of exit steam depending upon inlet quality

  • 42. 
    In case of impulse steam turbine

  • there is enthalpy drop in fixed and moving blades
  • there is enthalpy drop only in moving blades
  • there is enthalpy drop in nozzles
  • none of the above

  • 43. 
    The pressure on the two sides of the impulse wheel of a steam turbine

  • is same
  • is different
  • increases from one side to the other side
  • decreases from one side to the other side

  • 44. 
    In De Laval steam turbine

  • the pressure in the turbine rotor is approximately same as in con¬denser
  • the pressure in the turbine rotor is higher than pressure in the con¬denser
  • the pressure in the turbine rotor gradually decreases from inlet to exit from condenser
  • none from the above

  • 45. 
    Incase of reaction steam turbine

  • there is enthalpy drop both in fixed and moving blades
  • there is enthalpy drop only in fixed blades
  • there is enthalpy drop only in moving blades
  • none of the above

  • 46. 
    Curtis turbine is

  • reaction steam turbine
  • pressure velocity compounded steam turbine
  • pressure compounded impulse steam turbine
  • velocity compounded impulse steam turbine

  • 47. 
    Rateau steam turbine is

  • reaction steam turbine
  • velocity compounded impulse steam turbine
  • pressure compounded impulse steam turbine
  • pressure velocity compounded steam turbine

  • 48. 
    Parson’s turbine is

  • pressure compounded steam turbine
  • simple single wheel, impulse steam turbine
  • simple single wheel reaction steam turbine
  • multi wheel reaction steam turbine

  • 49. 
    For Parson’s reaction steam turbine, degree of reaction is

  • 75%
  • 100%
  • 50%
  • 60%

  • 50. 
    Reheat factor in steam turbines depends on

  • exit pressure only
  • stage efficiency only
  • initial pressures and temperature only
  • all of the above

  • 51. 
    The value of reheat factor normally varies from

  • 0.5 to 0.6
  • 0.9 to 0.95
  • 1.02 to 1.06
  • 1.2 to 1.6

  • 52. 
    Steam turbines are governed by the following methods

  • Throttle governing
  • Nozzle control governing
  • By-pass governing
  • all of the above

  • 53. 
    In steam turbines the reheat factor

  • increases with the increase in number of stages
  • decreases with the increase in number of stages
  • remains same irrespective of number of stages
  • none of the above

  • 54. 
    The thermal efficiency of the engine with condenser as compared to without condenser, for a given pressure and temperature of steam, is

  • higher
  • lower
  • same as long as initial pressure and temperature is unchanged
  • none of the above

  • 55. 
    In jet type condensers

  • cooling water passes through tubes and steam surrounds them
  • steam passes through tubes and cooling water surrounds them
  • steam and cooling water mix
  • steam and cooling water do not mix

  • 56. 
    In a shell and tube surface condenser

  • steam and cooling water mix to give the condensate
  • cooling water passes through the tubes and steam surrounds them
  • steam passes through the cooling tubes and cooling water surrounds them
  • all of the above varying with situation

  • 57. 
    In a surface condenser if air is removed, there is

  • fall in absolute pressure maintained in condenser
  • rise in absolute pressure maintained in condenser
  • no change in absolute pressure in the condenser
  • rise in temperature of condensed steam

  • 58. 
    The cooling section in the surface condenser

  • increases the quantity of vapour extracted along with air
  • reduces the quantity of vapour extracted along with air
  • does not affect vapour quantity extracted but reduces pump capacity of air extraction pump
  • none of the above

  • 59. 
    Edward’s air pump

  • removes air and also vapour from condenser
  • removes only air from condenser
  • removes only un-condensed vapour from condenser
  • removes air alongwith vapour and also the condensed water from condenser

  • 60. 
    In a steam power plant, the function of a condenser is

  • to maintain pressure below atmospheric to increase work output from the primemover
  • to receive large volumes of steam exhausted from steam prime mover
  • to condense large volumes of steam to water which may be used again in boiler
  • all of the above

  • 61. 
    In a regenerative surface condenser

  • there is one pump to remove air and condensate
  • there are two pumps to remove air and condensate
  • there are three pumps to remove air, vapour and condensate
  • there is no pump, the condensate gets removed by gravity

  • 62. 
    Evaporative type of condenser has

  • steam in pipes surrounded by water
  • water in pipes surrounded by steam
  • either (a) or (b)
  • none of the above

  • 63. 
    Pipes carrying steam are generally made up of

  • steel
  • cast iron
  • copper
  • aluminium

  • 64. 
    For the safety of a steam boiler the number of safety valves fitted are

  • four
  • three
  • two
  • one

  • 65. 
    Belt conveyer can be used to transport coal at inclinations upto

  • 30°
  • 60°
  • 80°
  • 90°

  • 66. 
    The maximum length of a screw conveyer is about

  • 30 metres
  • 40 metres
  • 60 metres
  • 100 metres

  • 67. 
    The efficiency of a modern boiler using coal and heat recovery equipment is about

  • 25 to 30%
  • 40 to 50%
  • 65 to 70%
  • 85 to 90%

  • 68. 
    The average ash content in Indian co als is about

  • 5%
  • 10%
  • 15%
  • 20%

  • 69. 
    Steam pressure in a steam power station, which is usually kept now-a-days is of the order of

  • 20 kgf/cm2
  • 50 kgf/cm2
  • 100 kgf/cm2
  • 150 kgf/cm2

  • 70. 
    The capacity of large turbo-generators varies from

  • 20 to 100 MW
  • 50 to 300 MW
  • 70 to 400 MW
  • 100 to 650 MW

  • 71. 
    Caking coals are those which

  • burn completely
  • burn freely
  • do not form ash
  • form lumps or masses of coke

  • 72. 
    Primary air is that air which is used to

  • reduce the flame length
  • increase the flame length
  • transport and dry the coal
  • provide air around burners for get¬ting optimum combustion

  • 73. 
    Secondary air is the air used to

  • reduce the flame length
  • increase the flame length
  • transport and dry the coal
  • provide air round the burners for getting optimum combustion

  • 74. 
    In coal preparation plant, magnetic separators are used to remove

  • dust
  • clinkers
  • iron particles
  • sand

  • 75. 
    Load carrying capacity of belt conveyor is about

  • 20 to 40 tonnes/hr
  • 50 to 100 tonnes/hr
  • 100 to 150 tonnes/hr
  • 150 to 200 tonnes/hr

  • 76. 
    Method which is commonly applied for unloading the coal for small power plant is

  • lift trucks
  • coal accelerators
  • tower cranes
  • belt conveyor

  • 77. 
    Example of overfeed type stoker is

  • chain grate
  • spreader
  • travelling grate
  • all of the above

  • 78. 
    TravelUng grate stoker can burn coals at the rates of

  • 50—75 kg/m per hour
  • 75—100 kg/m per hour
  • 100—150 kg/m per hour
  • 150—200 kg/m2 per hour

  • 79. 
    Blowing down of boiler water is the process

  • to reduce the boiler pressure
  • to increase the steam temperature
  • to control the solid concentration in the boiler water by removing some of the concentrated saline water
  • none of the above

  • 80. 
    The value of the reheat factor is of the order of

  • 0.8 to 1.0
  • 1.0 to 1.05
  • 1.1 to 1.5
  • above 1.5

  • 81. 
    . Compounding of steam turbine is done for

  • reducing the work done
  • increasing the rotor speed
  • reducing the rotor speed
  • balancing the turbine
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