Power Plant Engineering Mcq Pdf Download

61. The highest proportion of total heat supplied to a diesel engine goes to

(a) useful output.
(b) heat lost to exhaust gases.
(c) heat lost to cooling water.
(d) heat lost to friction, windage and radiation losses.

62. Which of the following diesel engines have minimum air consumption per BHP ?

(a) 2 stroke, air injection.
(b) 4 stroke, air injection.
(c) 4 stroke, mechanical injection.
(d) All of the above have almost equal air consumption.

63. Heating value of diesel oil is around

(a) 4,000 kcals/kg.
(b) 10,000 kcals/kg.
(c) 15,000 kcals/kg.
(d) 20,000 kcals/kg.

64. In a four stroke petrol engine during suction stroke

(a) only petrol is sucked in.
(b) only air is sucked in.
(c) mixture of petrol and air is sucked in.
(d) any combustible gas is sucked in.

65. In a four stroke engine, the four operations (suction, compression, expansion and exhaust) are completed in……….revolution(s) of crankshaft.

(a) eight
(b) four
(c) two
(d) one

65. In a two stroke engine, the four operations (suction, compression, expansion and exhaust) are completed in…….revolution(s) of crankshaft.

(a) one
(b) two
(c) four
(d) eight

66. Most of the heat generated in IC engines goes to

(a) cooling water.
(b) exhaust gases.
(c) friction, windage and radiation loses.
(d) lubricating oil.

67. Reciprocating motion of piston is converted into rotary one by

(a) crank shaft.
(b) connecting rod.
(c) gudgeon pin.
(d) gear box.

68. A two stroke engine may be identified by

(a) cooling system.
(b) lubrication system.
(c) absence of valves.
(d) any of the above.

69. The performance of engines of different outputs, speeds and sizes can be compared on the basis of

(a) specific fuel consumption.
(b) cylinder volume.
(c) compression ratio.
(d) piston size.

70. The thermal efficiency of a diesel engine in comparison to that of a petrol engine is

(a) lower.
(b) higher.
(c) the same.
(d) may be lower or higher.

71. In an multi-cylinder engine the firing order should be in particular sequence because it

(a) will operate ignition system smoothly.
(b) will give smooth turning moment.
(c) will provide the best performance of the engine.
(d) all of the above.

72. High output diesel engines are started by

(a) self starter.
(b) compressed air.
(c) battery.
(d) cranking.

73. The temperature of cooling water leaving the diesel engine should not exceed

(a) 25°C
(b) 40°C
(c) 70°C
(d) 85°C

74. Air filter is used in

(a) steam power plants.
(b) nuclear power plants.
(c) hydropower plants.
(d) diesel power plants.

75. For supercharging of diesel engines, the air is supplied through

(a) injector.
(b) reciprocating compressor.
(c) centrifugal blower.
(d) any of the above.

76. Supercharging of diesel engines

(a) supply pressurized air during suction.
(b) increases the power output of the engine.
(c) reduces the specific fuel consumption.
(d) both (a) and (b).

77. The temperature at which a lubricating oil will give sufficient vapors to form a combustible mixture with air is called the

(a) flash point.
(b) pour point.
(c) fire point.
(d) combustion point.

78. Which of the following will be the lowest for a lubricating oil ?

(a) Flash point.
(b) Pour point.
(c) Fire point.
(d) Combustion point.

79. Fire and flash points of oils are important from the point of view of

(a) heating value.
(b) viscosity.
(c) ignition and storage hazards.
(d) tendency of freezing during winter.

80. For larger output diesel electric power plants the engines used are

(a) horizontal type.
(b) vertical type, multi-cylinder and supercharged.
(c) air cooled.
(d) low rpm.