1. Fluid is a substance that
(a) cannot be subjected to shear forces
(b) always expands until it fills any container
(c) has the same shear stress.at a point regardless of its motion
(d) cannot remain at rest under action of any shear force
(e) flows.
Ans: d

2. Fluid is a substance, which offers no resistance to change of
(a) pressure
(b) flow
(c) shape
(d) volume
(e) temperature.
Ans: c

3. Practical fluids
(a) are viscous
(b) possess surface tension
(c) are compressible
(d) possess all the above properties
(e) possess none of the above properties.
Ans: d

4. In a static fluid
(a) resistance to shear stress is small
(b) fluid pressure is zero
(c) linear deformation is small
(d) only normal stresses can exist
(e) viscosity is nil.
Ans: d

5. A fluid is said to be ideal, if it is
(a) incompressible
(b) inviscous
(c) viscous and incompressible
(d) inviscous and compressible
(e) inviscous and incompressible.
Ans: e

6. An ideal flow of any fluid must fulfil the following
(a) Newton's law of motion
(b) Newton's law of viscosity
(c) Pascal' law
(d) Continuity equation
(e) Boundary layer theory.
Ans: d

7. If no resistance is encountered by displacement, such a substance is known as
(a) fluid
(b) water
(c) gas
(d) perfect solid
(e) ideal fluid.
Ans: e

8. The volumetric change of the fluid caused by a resistance is known as
(a) volumetric strain
(b) volumetric index
(c) compressibility
(e) cohesion.
Ans: c

9. Liquids
(a) cannot be compressed
(b) occupy definite volume
(c) are not affected by change in pressure and temperature
(d) are not viscous
(e) none of the above.
Ans: e

10. Density of water is maximum at
(a) 0°C
(b) 0°K
(c) 4°C
(d) 100°C
(e) 20°C.
Ans: c

11. The value of mass density in kgfsec
2/m4 for water at 0°C is
(a) 1
(b) 1000
(c) 100
(d) 101.9
(e) 91
Ans: d

12. Property of a fluid by which its own molecules are attracted is called
(b) cohesion
(c) viscosity
(d) compressibility
(e) surface tension.
Ans: b

13. Mercury does not wet glass. This is due to property of liquid known as
(b)     cohesion
(c)     surface tension
(d)     viscosity
(e)     compressibility.
Ans: c

14. The property of a fluid which enables it to resist tensile stress is known as
(a) compressibility
(b) surface tension
(c) cohesion
(e) viscosity.
Ans: c

15. Property of a fluid by which molecules of different kinds of fluids are attracted to each other is called
(b) cohesion
(c) viscosity
(d) compressibility
(e) surface tension.
Ans: a

16. The specific weight of water is 1000 kg/m3
(a) at normal pressure of 760 mm
(b) at 4°C temperature
(c) at mean sea level
(d) all the above
(e) none of the above.
Ans: d

17. Specific weight of water in S.I. units is equal to
(a) 1000 N/m3
(b) 10000 N/m3
(c) 9.81x l03 N/m3
(d) 9.81x l06N/m3
(e) 9.81 N/m3.
Ans: c

18. When the flow parameters at any given instant remain same at every point, then flow is said to be
(a) quasi static
(c) laminar
(d) uniform
(e) static.
Ans: d

19. Which of the following is demensionless
(a) specific weight
(b) specific volume
(c) specific speed
(d) specific gravity
(e) specific viscosity.
Ans: d

20. The normal stress in a fluid will be constant in all directions at a point only if
(a) it is incompressible
(b) it has uniform viscosity
(c) it has zero viscosity
(d) it is frictionless
(e) it is at rest.
Ans: e

21. The pressure at a point in a fluid will not be same in all the directions when the fluid is
(a)     moving
(b)     viscous
(c) viscous and static
(d) inviscous and moving
(e) viscous and moving.
Ans: e

22. An object having 10 kg mass weighs 9.81kg on a spring balance. The value of 'g' at this place is
(a) 10m/sec2
(b) 9.81 m/sec2
(c) 10.2/m sec
(d) 9.75 m/sec2
(e) 9 m/sec .
Ans: a

23. The tendency of a liquid surface to contract is due to the following property
(a) cohesion
(c) viscosity
(d) surface tension
(e) elasticity.
Ans: d

24. The surface tension of mercury at normal temperature compared to that of water is
(a)     more
(b)     less
(c) same
(d) more or less depending on size of glass tube
(e) none of the above.
Ans: a

25. A perfect gas
(a) has constant viscosity
(b) has zero viscosity
(c) is in compressible
(d) is of theoretical interest
(e) none of the above.
Ans: e

26. For very great pressures, viscosity of moss gases and liquids
(a)     remains same
(b)     increases
(c) decreases
(d) shows erratic behavior
(e) none of the above.
Ans: d

27. A fluid in equilibrium can't sustain
(a) tensile stress
(b) compressive stress
(c) shear stress
(d) bending stress
(e) all of the above.
Ans: c

28. Viscosity of water in comparison to mercury is
(a)    higher
(b)    lower
(c)    same
(d)    higher/lower depending on temperature
(e)    unpredictable.
Ans: a

29. The bulk modulus of elasticity with increase in pressure
(a) increases
(b) decreases
(c) remains constant
(d) increases first up to certain limit and then decreases
(e) unpredictable.
Ans: a

30. The bulk modulus of elasticity
(a) has the dimensions of 1/pressure
(b) increases with pressure
(c) is large when fluid is more compressible
(d) is independent of pressure and viscosity
(e) is directly proportional to flow.
Ans: b

31. A balloon lifting in air follows the following principle
(a) law of gravitation
(b) Archimedes principle
(c) principle of buoyancy
(d) all of the above
(e) continuity equation.
Ans: d

32. The value of the coefficient of compressibility for water at ordinary pressure and temperature in kg/cm  is equal to
(a) 1000
(b) 2100
(c) 2700
(d) 10,000
(e) 21,000.
Ans: e

33. The increase of temperature results in
(a) increase in viscosity of gas
(b) increase in viscosity of liquid
(c) decrease in viscosity of gas
(d) decrease in viscosity of liquid
(e) (a) and (d) above.
Ans: d

34. Surface tension has the units of
(a) newtons/m
(b) newtons/m
(c) new tons/m
(d) newtons
(e) newton m.
Ans: c

35. Surface tension
(a) acts in the plane of the interface normal to any line in the surface
(b) is also known as capillarity
(c) is a function of the curvature of the interface
(d) decreases with fall in temperature
(e) has no units.
Ans: a

36. The stress-strain relation of the newtoneon fluid is
(a) linear
(b) parabolic
(c) hyperbolic
(d) inverse type
(e) none of the above.
Ans: a

37. A liquid compressed in cylinder has a volume of 0.04 m3 at 50 kg/cm2 and a volume of 0.039 m3 at 150 kg/cm2. The bulk modulus of elasticity of liquid is
(a) 400 kg/cm2
(b) 4000 kg/cm2
(c) 40 x 105 kg/cm2
(d) 40 x 106 kg/cm2
(e) none of the above.
Ans: b

38. The units of viscosity are
(a) metres2 per sec
(b) kg sec/metre
(c) newton-sec per metre2
(d) newton-sec  per meter
(e) none of the above.
Ans: b

39. Kinematic viscosity is dependent upon
(a) pressure
(b) distance
(c) level
(d) flow
(e) density.
Ans: e

40. Units of surface tension are
(a) energy/unit area
(b) distance
(c) both of the above
(d) it has no units
(e) none of the above.
Ans: c

41. Which of the following meters is not associated with viscosity
(a) Red wood
(b) Say bolt
(c) Engler
(d) Orsat
(e) none of the above.
Ans: d

42. Choose the correct relationship
(a) specific gravity = gravity x density
(b) dynamicviscosity = kinematicviscosity x density
(c) gravity = specific gravity x density
(d) kinematicviscosity = dynamicviscosity x density
(e) hydrostaticforce = surface tension x gravity.
Ans: b

43. Dimensions of surface tension are
(a) MlL°T2
(b) MlL°Tx
(c) MlL r2
(d) MlL2T2
(e) MlL°t.
Ans: a

44. For manometer, a better liquid combination is one having
(a) higher surface tension
(b) lower surface tension
(c) surface tension is no criterion
(d) high density and viscosity
(e) low density and viscosity.
Ans: a

45. If mercury in a barometer is replaced by water, the height of 3.75 cm of mercury will be following cm of water
(a) 51 cm
(b) 50 cm
(c) 52 cm
(d) 52.2 cm
(e) 51.7 cm.
Ans: a

46. Choose the wrong statement.
Alcohol is used in manometer, because
(a) its vapour pressure is low
(b) it provides suitable meniscus for the inclined tube
(c) its density is less
(d) it provides longer length for a given pressure difference
(e) it provides accurate readings.
Ans: a

47. Increase in pressure at the outer edge of a drum of radius R due to rotation at corad/sec, full of liquid of density p will be
(a) pco2/?2
(b) pco2/?2/2
(c) 2pa2R2
(d) pa2R/2
(e) none of the above.
Ans: b

48. The property of fluid by virtue of which it offers resistance to shear is called
(a) surface tension
(c) cohesion
(d) viscosity
(e) all of the above.
Ans: d

49. Choose the wrong statement
(a) fluids are capable of flowing
(b) fluids conform to the shape of the containing vessels
(c) when in equilibrium, fluids cannot sustain tangential forces
(d) when in equilibrium, fluids can sustain shear forces
(e) fluids have some degree of comprehensibility and offer little resistance to form.
Ans: d

50. The density of water is 1000 kg/m3 at
(a) 0°C
(b) 0°K
(c) 4°C (d) 20°C
(e) all temperature.
Ans: c

51. If w is the specific weight of liquid and k the depth of any point from the surface, then pressure intensity at that point will be
(a) h
(b) wh
(c) w/h
(d) h/w
(e) h/wh.
Ans: b

52. Choose the wrong statement
(a) Viscosity of a fluid is that property which determines the amount of its resistance to a shearing force
(b) Viscosity is due primarily to interaction between fluid molecules
(c) Viscosity of liquids decreases with in-crease in temperature
(d) Viscosity of liquids is appreciably affected by change in pressure
(e) Viscosity is expressed as poise, stoke, or saybolt seconds.
Ans: d

53. The units of kinematic viscosity are
(a) metres2 per sec
(b) kg sec/metre
(c) newton-sec per metre
(d) newton-sec per metre
(e) none of the above.
Ans: a

54.  The ratio of absolute viscosity to mass density is known as
(a) specific viscosity
(b) viscosity index
(c) kinematic viscosity
(d) coefficient of viscosity
(e) coefficient of compressibility.
Ans: c

55.   Kinematic viscosity is equal to
(a) dynamic viscosity/density
(b) dynamicviscosity x density
(c) density/dynamic viscosity
(d) 1/dynamicviscosity x density
(e) same as dynamic viscosity.
Ans: a

56.   Which of the following is the unit of kinematic viscosity
(a) pascal
(b) poise
(c) stoke
(e) none of the above.
Ans: c

57.   A one dimensional flow is one which
(a) is uniform flow
(b) is steady uniform flow
(c) takes place in straight lines
(d) involves zero transverse component of flow
(e) takes place in one dimension.
Ans: d

58.  Alcohol is used in manometers because
(a) it has low vapour pressure
(b) it is clearly visible
(c) it has low surface tension
(d) it can provide longer column due to low density
(e) is provides suitable meniscus.
Ans:  d

59. A pressure of 25 m of head of water is equal to
(a) 25 kN/m2
(b) 245 kN/m2
(c) 2500 kN/m2
(d) 2.5kN/m2
(e) 12.5 kN/m2.
Ans: b

60. Specific weight of sea water is more that of pure water because it contains
(a) dissolved air
(b) dissolved salt
(c) suspended matter
(d) all of the above
(e) heavy water.
Ans: d

61. If 850 kg liquid occupies volume of one cubic meter, men 0.85 represents its
(a) specific weight
(b) specific mass
(c) specific gravity
(d) specific density
(e) none of the above.
Ans: c

62. Free surface of a liquid tends to contract to the smallest possible area due to force of
(a) surface tension
(b) viscosity
(c) friction
(d) cohesion
Ans: a

63. A bucket of water is hanging from a spring balance. An iron piece is suspended into water without touching sides of bucket from another support. The spring balance reading will
(a) increase
(b) decrease
(c) remain same
(d) increase/decrease depending on depth of immersion
(e) unpredictable.
Ans: c

64. Falling drops of water become spheres due to the property of
(b) cohesion
(c) surface tension
(d) viscosity
(e) compressibility.
Ans: c

65. A liquid would wet the solid, if adhesion forces as compared to cohesion forces are
(a) less
(b) more
(c) equal
(d) less at low temperature and more at high temperature
(e) there is no such criterion.
Ans: b

66. If cohesion between molecules of a fluid is greater than adhesion between fluid and glass, then the free level of fluid in a dipped glass tube will be
(a) higher than the surface of liquid
(b) the same as the surface of liquid
(c) lower than the surface of liquid
(d) unpredictable
(e) none of the above.
Ans: c

67. The point in the immersed body through which the resultant pressure of the liquid may be taken to act is known as
(a) meta center
(b) center of pressure
(c) center of buoyancy
(d) center of gravity
(e) none of the above.
Ans: b

68. The total pressure on the surface of a vertical sluice gate 2 m x 1 m with its top 2 m surface being 0.5 m below the water level will be
(a) 500 kg
(b) 1000 kg
(c) 1500 kg
(d) 2000 kg
(e) 4000 kg.
Ans: d

69. The resultant upward pressure of a fluid on a floating body is equal to the weight of the fluid displaced by the body. This definition is according to
(a) Buoyancy
(b) Equilibrium of a floating body
(c) Archimedes' principle
(d) Bernoulli's theorem
(e) Metacentric principle.
Ans: c

70. The resultant upward pressure of the fluid on an immersed body is called
(a) upthrust
(b) buoyancy
(c) center of pressure
(d) all the above are correct
(e) none of above is correct.
Ans: b

71. The conditions for the stable equilibrium of a floating body are
(a) the meta-center should lie above the center of gravity
(b) the center of buoyancy and the center of gravity must lie on the same vertical line
(c) a righting couple should be formed
(d) all the above are correct
(e) none of the above is correct.
Ans: d

72. Poise is the unit of
(a) surface tension
(b) capillarity
(c) viscosity
(d) shear stress in fluids
(e) buoyancy.
Ans: c

73. Metacentric height is given as the distance between
(a) the center of gravity of the body and the meta center
(b) the center of gravity of the body and the center of buoyancy
(c) the center of gravity of the body and the center of pressure
(d) center of buoyancy and metacentre
(e) none of the above.
Ans: a

74. The buoyancy depends on
(a) mass of liquid displaced
(b) viscosity of the liquid
(c) pressure of the liquid displaced
(d) depth of immersion
(e) none of the above.
Ans: a

75. The center of gravity of the volume of the liquid displaced by an immersed body is called
(a) meta-center
(b) center of pressure
(c) center of buoyancy
(d) center of gravity
(e) none of the above.
Ans: c

76. A piece of metal of specific gravity 13.6 is placed in mercury of specific gravity 13.6, what fraction of it volume is under mercury?
(a) the metal piece will simply float over the mercury
(b) the metal piece will be immersed in mercury by half
(c) whole of the metal piece will be immersed with its top surface just at mercury level
(d) metal piece will sink to the bottom
(e) none of the above.
Ans: c

77. The angle of contact in case of a liquid depends upon
(a) the nature of the liquid and the solid
(b) the material which exists above the free surface of the liquid
(c) both of die above
(d) any one of the above
(e) none of die above.
Ans: c

78. Free surface of a liquid behaves like a sheet and tends to contract to smallest possible area due to the
(a) force of adhesion
(b) force of cohesion
(c) force of friction
(d) force of diffusion
(e) none of die above.
Ans: b

79.  Rain drops are spherical because of
(a) viscosity
(b) air resistance
(c) surface tension forces
(d) atmospheric pressure
(e) none of the above.
Ans: c

80.  Surface energy per unit area of a surface is numerically equal to     ..
(a) atmospheric pressure
(b) surface tension
(c) force of adhesion
(d) force of cohesion
(e) viscosity.
Ans: b

81. The capillary rise at 20°C in a clean glass tube of 1 mm bore containing water is approximately
(a) 1 mm
(b) 5 mm
(c) 10 mm
(d) 20 mm
(e) 30 mm.
Ans: e

82.  The difference of pressure between the inside and outside of a liquid drop is
(a)p = Txr
(b)p = T/r
(c) p = T/2r
(d)p = 2T/r
(e) none of the above.
Ans: d

83.  If the surface of liquid is convex, men
(a) cohesion pressure is negligible
(b) cohesion pressure is decreased
(c) cohesion pressure is increased
(d) there is no cohesion pressure
(e) none of the above.
Ans: c

84. To avoid vaporisation in the pipe line, the pipe line over the ridge is laid such that it is not more than
(a) 2.4 m above the hydraulic gradient
(b) 6.4 m above the hydraulic gradient
(c) 10.0 m above the hydraulic gradient
(d) 5.0 above the hydraulic gradient
(e) none of the above.
Ans: b

85. To avoid an interruption in the flow of a syphon, an air vessel is provided
(a) at the inlet
(b) at the outlet
(c) at the summit
(d) ay nay point between inlet and outlet
(e) none of the above.
Ans: c

86. The vapour pressure over the concave surface is
(a) less man the vapour pressure over the plane surface
(b) equal to the vapour pressure over the plane surface
(c) greater than the vapour pressure over the plane surface
(d) zero
(e) none of the above.
Ans: a

87. The property by virtue of which a liquid opposes relative motion between its different layers is called
(a) surface tension
(b) co-efficient of viscosity
(c) viscosity
(d) osmosis
(e) cohesion.
Ans: c

88. The process of diffusion of one liquid into the other through a semi-permeable membrane is called
(a) viscosity
(b) osmosis
(c) surface tension
(d) cohesion
(e) diffusivity.
Ans: b

89. The units of dynamic or absolute viscosity are
(a) metres2 per sec
(b) kg sec/meter
(c) newton-sec per meter
(d) newton-sec2 per meter
(e) none of the above.
Ans: c

90. The continuity equation is connected with
(a) viscous/unviscous fluids
(b) compressibility of fluids
(c) conservation of mass
(e) open channel/pipe flow.
Ans: c

91. The rise or depression of liquid in a tube due to surface tensionwim increase in size of tube will
(a) increase
(b) remain unaffected
(c) may increase or decrease depending on the characteristics of liquid
(d) decrease
(e) unpredictable.
Ans: d

92. Liquids transmit pressure equally in all the directions. This is according to
(a) Boyle's law
(b) Archimedes principle
(c) Pascal's law
(d) Newton's formula
(e) Chezy's equation.
Ans: c

93. Capillary action is due to the
(a) surface tension
(b) cohesion of the liquid
(c) adhesion of the liquid molecules and the molecules on the surface of a solid
(d) all of the above
(e) none of the above.
Ans: d

94. Newton's law of viscosity is a relationship between
(a) shear stress anctthejiate of angular distortion
(b) shear stress and viscosity
(c) shear stress, velocity and viscosity
(d) pressure, velocity and viscosity
(e) shear stress, pressure and rate of angular distortion.
Ans: a

95. The atmospheric pressure with rise in altitude decreases
(a) linearly
(b) first slowly and then steeply
(c) first steeply and then gradually
(d) unpredictable
(e) none of the above.
Ans: b

96. Pressure of the order of 10"' torr can be measured by
(a) Bourdon tube
(b) Pirani Gauge
(c) micro-manometer
(d) ionisastion gauge
(e) McLeod gauge.
Ans: d

97. Operation of McLeod gauge used for low pressure measurement is based on the principle of
(a) gas law
(b) Boyle's law
(c) Charle's law
(d) Pascal's law
(e) McLeod's law.
Ans: b

98. An odd shaped body weighing 7.5 kg and occupying 0.01 m3 volume will be completely submerged in a fluid having specific gravity of
(a) 1
(b) 1.2
(c) 0.8
(d) 0.75
(e) 1.25.
Ans: d

99. In an isothermal atmosphere, the pressure
(a) decreases linearly with elevation
(b) remains constant
(c) varies in the same way as the density
(d) increases exponentially with elevation
(e) unpredictable.
Ans: c

100. Mercury is often used in barometer because
(a) it is the best liquid
(b) the height of barometer will be less
(c) its vapour pressure is so low that it may be neglected
(d) both (b) and (c)
(e) it moves easily.
Ans: d

101. Barometer is used to measure
(a) pressure in pipes, channels etc.
(b) atmospheric pressure
(c) very low pressure
(d) difference of pressure between two points
(e) rain level.
Ans: b

102. Which of the following instrument can be used for measuring speed of a submarine moving in deep sea
(a) Venturimeter
(b) Orifice plate
(c) hot wire anemometer
(d) rotameter
(e) pitot tube.
Ans: e

103. Which of the following instrument can be used for measuring speed of an aeroplane
(a) Venturimeter
(b) Orifice plate
(c) hot wire anemometer
(d) rotameter
(e) pitot tube.
Ans: e

104. Piezometer is used to measure
(a) pressure in pipe, channels etc.
(b) atmospheric pressure
(c) very low pressures
(d) difference of pressure between two points
(e) flow.
Ans: c

105. Which of the following instruments is used to measure flow on the application of Bernoulli's theorem
(a) Venturimeter
(b) Orifice plate
(c) nozzle
(d) pitot tube
(e) all of the above.
Ans: e

106. The speed of sound in a ideal gas varies directly as its
(a) pressure
(b) temperature
(c) density
(d) modulus of elasticity
(e) absolute temperature,
Ans: e

107. Dynamic viscosity of most of the liquids with rise in temperature
(a) increases
(b) decreases
(a) remains unaffected
(d) unpredictable
(e) none of the above.
Ans: b

108. Dynamic viscosity of most of the gases with rise in temperature
(a) increases
(b) decreases
(c) remains unaffected
(d) unpredictable
(e) none of the above.
Ans: a

109. A metal with specific gravity of o floating in a fluid of same specific gravity a will
(a) sink to bottom
(b) float over fluid
(c) partly immersed
(d) be fully immersed with top surface at fluid surface
(e) none of the above.
Ans: d

110. Euler's dimensionless number relates the following
(a) inertial force and gravity
(b) viscous force and inertial force
(c) viscous force and buoyancy force
(d) pressure force and inertial force
(e) pressure force and viscous force.
Ans: d

111. Manometer is used to measure
(a) pressure in pipes, channels etc.
(b) atmospheric pressure
(c) very low pressure
(d) difference of pressure  between two points
(e) velocity.
Ans: a

112. Which of the following manometer has highest sensitivity
(a) U-tube with water
(b) inclined U-tube
(c) U-tube with mercury
(d) micro-manometer with water
(e) displacement type.
Ans: d

113. In order to increase sensitivity of U-tube manometer, one leg is usually inclined by angle 9. Sensitivity of inclined tube to sensitivity of U-tube is equal to
(a) sin 9
(b) sin 9
(c) cas 9
(d) cos 9
(e) tan 9.
Ans: b

114. Working principle of dead weight pressure gauge tester is based on
(a) Pascal's law
(b) Dalton's law of partial pressure
(c) Newton's law of viscosity .
(e) Second law of thermodynamic.
Ans: a

115. The resultant of all normal pressures acts
(a) at e.g. of body
(b) at center of pressure
(c) vertically upwards
(d) at metacentre
(e) vertically downwards.
Ans: c

116. Center of pressure compared to e.g. is
(a) above it
(b) below it.
(c) at same point
(d) above or below depending on area of body
(e) none of the above.
Ans: b

117. Metacentric height is the distance between the metacentre and
(a) water surface
(b) center of pressure
(c) center of gravity
(d) center of buoyancy
(e) none of the above.
Ans: c

118. The resultant upward pressure of the fluid on an immersed body due to its tendency to uplift the sub-merged body is called
(a) upthrust
(b) reaction
(c) buoyancy
(d) metacentre
(e) center of pressure.
Ans: c

119. The center of pressure of a surface subjected to fluid pressure is the point
(a) on the surface at which resultant pres-sure acts
(b) on the surface at which gravitational force acis
(c) at which all hydraulic forces meet
(d) similar to metacentre
(e) where pressure equivalent to hydraulic thrust will act.
Ans: a

120. Buoyant force is
(a) the resultant force acting on a floating body
(b) the resultant force on a body due to the fluid surrounding it
(c) equal  to  the  volume  of liquid dis-placed
(d) the force necessary to maintain equilibrium of a submerged body
(e) none of the above.
Ans: b

121. The horizontal component of buoyant force is
(a) negligible
(b) same as buoyant force
(c) zero
Ans: c

122.  The line of action of the buoyant force acts through the
(a) centroid of the volume of fluid vertically above the body
(b) centre of the volume of floating body
(c) center of gravity of any submerged body
(d) centriod of the displaced volume of fluid
(e) none of the above.
Ans: d

123.   Center of buoyancy is the
(a) centroid of the displaced volume of fluid
(b) center of pressure of displaced volume
(c) e.g. of floating 'body
(d) does not exist
(e) none of the above.
Ans: a

124.   A body floats in stable equilibrium
(a) when its meatcentric height is zero
(b) when the metancentre is above e.g.
(c) when its e.g. is below it's center of buoyancy
(d) metacentre has nothing to do with position of e.g. for determining stability
(e) none of the above.
Ans: b

125.   A piece weighing 3 kg in air was found to weigh 2.5 kg when submerged in water. Its specific gravity is
(a) 1
(b) 5
(c) 7
(d) 6
Ans: d

126. The total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at the centriod, if
(a) the area is horizontal
(b) the area is vertical
(c) the area is inclined
(d) all of the above
(e) none of the above.
Ans: d

127. A square surface 3 m x 3 m lies in a vertical line in water pipe its upper edge at water surface. The hydrostatic force on square surface is
(a) 9,000 kg
(b) 13,500 kg
(c) 18,000 kg
(d) 27,000 kg
(e) 30,000 kg.
Ans: b

128. The depth of the center of pressure on a vertical rectangular gate 8 m wide and 6 m high, when the water surface coincides with the top of the gate, is
(a) 2.4 m
(b) 3.0 m
(c) 4.0 m
(d)"2.5 m
(e) 5.0 m.
Ans: b

129. If the atmospheric pressure on the surface of an oil tank (sp. gr. 0.8) is 0.2 kg/cm", the pressure at a depth of 50 m below the oil surface will be
(a) 2 meters of water column
(b) 3 meters of water column
(c) 5 meters of water column
(d) 6 meters of water Column
(e) 7 meters of water column.
Ans: d

130. Metacentre is the point of intersection of
(a) vertical upward force through e.g. of body and center line of body
(b) buoyant force and the center line of body
(c) mid point between e.g. and center of buoyancy
(d) all of the above
(e) none of the above.
Ans: b

131. Choose the wrong statement
(a) The horizontal component of the hydro-static force on any surface is equal to the normal force on the vertical projection of the surface
(b) The horizontal component acts through the center of pressure for the vertical projection
(c) The vertical component of the hydrostatic force on any surface is equal to the weight of the volume of the liquid above the area
(d) he vertical component passes through the center of pressure of the volume
(e) Center of pressure acts at a greater depth than center of gravity.
Ans: d

132. For a body floating in a liquid the normal pressure exerted by the liquid acts at
(a) bottom surface of the body
(b) e.g. of the body
(c) metacentre
(d) all points on the surface of the body
(e) all of the above.
Ans: d

133. Choose the wrong statement
(a) any weight, floating or immersed in a liquid, is acted upon by a buoyant force
(p) Buoyant force is equal to the weight of the liquid displaced
(c) The point through which buoyant force acts, is called the center of buoyancy
(d) Center of buoyancy is located above the center of gravity of the displaced liquid v
(e) Relative density of liquids can be determined by means of the depth of flotation of hydrometer.
Ans: d

134. According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to
(a) the weight of the body
(b) more than the weight of the body
(c) less than the weight of the body
(d) weight of the fluid displaced by the body
(e) weight of body plus the weight of the fluid displaced hy the body.
Ans: d

135. When a body floating in a liquid, is displaced slightly, it oscillates about
(a) e.g. of body
(b) center of pressure
(c) center of buoyancy
(d) metacentre
(e) liquid surface.
Ans: d

136. Buoyant force is
(a) resultant force acting on a floating body
(b) equal to the volume of liquid displaced
(c) force necessary to keep a body in equilibrium
(d) the resultant force on a body due to the fluid surrounding it
(e) none of the above.
Ans: d

137. Ratio of inertia force to surface Jension is known as
(a) Mach number
(b) Froude number
(c) Reynold's number
(d) Weber's number
(e) none of the above.
Ans: d

138. A ship whose hull length is 100 m is to travel at 10 m/sec. For dynamic similarity,
at what velocity should a 1:25 model be towed through water ?
(a) 10 m/sec
(b) 25 m/sec
(c) 2 m/sec
(d) 50 m/sec
(e) 250 m/sec.
Ans: c

139. A model of a reservior is drained in 4 mts by opening the sluice gate. The model scale is 1: 225. How long should it take to empty the prototype ?
(a) 900 minutes
(b) 4 minutes
(c) 4 x (225)3/2 minutes
(d) 4 (225)1/3 minutes
(e) 4 x V225 minutes.
Ans: e

140. A model of torpedo is tested in a towing tank at a velocity of 25 m/sec. The prototype is expected to attain a velocity of 5 m/sec. What model scale has been used ?
(a) 1 : 5
(b) 1 : 2.5
(c) 1 :25
(d) 1:V5"
(e) 1 : 53/2
Ans: a

141. Ratio of inertia force to elastic force is known as
(a) Mach number
(b) Froude number
(c) Reynold's number
(d) Weber's number
(e) none of the above.
Ans: a

142. For a floating body to be in stable equilibrium, its metacentre should be
(a) below the center of gravity
(b) below the center of buoyancy
(c) above the center of buoyancy
(d) between e.g. and center of pressure
(e) above the center of gravity.
Ans: e

143. For a floating body to be in equilibrium
(a) meta centre should be above e.g.
(b) centre of buoyancy and e.g. must lie on same vertical plane
(c) a righting couple should be formed
(d) all of the above
(e) none of the above.
Ans: d

144. The two important forces for a floating body are
(a) buoyancy, gravity
(b) buoyancy, pressure
(c) buoyancy, inertial
(d) inertial, gravity
(e) gravity, pressure.
Ans: a

145. Choose the wrong statement
(a) The center of buoyancy is located at the center of gravity of the displaced liquid
(b) For stability of a submerged body, the center of gravity of body must lie directly below the center of buoyancy
(c) If e.g. and center of buoyancy coincide, the submerged body must lie at neutral equilibrium for all positions
(d) For stability of floating cylinders or spheres, the e.g. of body must lie below the center of buoyancy
(e) All floating bodies are stable.
Ans: e

146. Center of pressure on an inclined plane is
(a) at the centroid
(b) above the centroid
(c) below the centroid
(d) at metacentre
(e) at center of pressure.
Ans: c

147. An open vessel of water is accelerated up an inclined plane. The free water surface will
(a) be horizontal
(b) make an angle in direction of inclination of inclined plane
(c) make an angle in opposite direction to inclination of inclined plane
(d) any one of above is possible
(e) none of the above.
Ans: c

148. The line of action of the buoyant force acts through the centroid of the
(a) submerged body
(b) volume of the floating body
(c) volume of the fluid vertically above the body
(d) displaced volume of the fluid
(e) none of the above.
Ans: d

149. Resultant pressure of the liquid in the case of an immersed body acts through
(a) centre of gravity
(b) centre of pressure
(c) metacentre
(d) centre of buoyancy
(e) in between e.g. and centre of pressure.
Ans: b

150. The centre of gravity of the volume of the liquid displaced by an immersed body is called
(a) centre of gravity
(b) centre of pressure
(c) metacentre
(d) centre of buoyancy
(e) centroid.
Ans: d

176. Differential monometer is used to measure
(a) pressure in pipes, channels etc.
(b) atmospheric pressure
(c) very low pressure
(d) difference of pressure  between two points
(e) velocity in pipes
Ans: d

177. The pressure in the air space above an oil (sp. gr. 0.8) surface in a tank is 0.1 kg/cm".
The pressure at 2.5 m below the oil surface will be
(a) 2 metres of water column
(b) 3 metres of water column
(c) 3.5 metres of water column
(d) 4 m of water column
(e) none of the above.
Ans: b

178. The time oscillation of a floating body with increase in metacentric height will be
(a) same
(b) higher
(c) lower
(d) lower/higher depending on weight of body
(e) unpredictable.
Ans: c

179. In an immersed body, centre of pressure is
(a) at the centre of gravity
(b) above the centre of gravity
(c) below be centre of gravity
(d) could be above or below e.g. depend¬ing on density of body and liquid
(e) unpredictable.
Ans: c

180. The normal stress is same in all directions at a point in a fluid
(a) only when the fluid is frictionless
(b) only when the fluid is incompressible and has zero viscosity
(c) when there is no motion of one fluid layer relative to an adjacent layer
(d) irrespective of the motion of one fluid layer relative to an adjacent layer
(e) in case of an ideal fluid.
Ans: c

181. Select the correct statement
(a) Local atmospheric pressure depends upon elevation of locality only
(b) Standard atmospheric pressure is the mean local atmospheric pressure a* sea level
(c) Local atmospheric pressure is always below standard atmospheric pressure
(d) A barometer reads the difference be-tween local and standard atmospheric pressure
(e) Gauge piessure is equal to atmospheric pressure plus instrument reading.
Ans: b

184. For measuring flow by a venturimeter, if should be installed in
(a) vertical line
(b) horizontal line
(c) inclined line with flow downward
(d) inclined line with upward flow\
(e) in any direction and in any location.
Ans: e

185. Total pressure on a lmxlm gate immersed vertically at a depth of 2 m below the free water surface will be
(a) 1000 kg
(b) 4000 kg
(c) 2000 kg
(d) 8000 kg
(e)  16000 kg.
Ans: a

186. Hot wire anemometer is used to measure
(a) pressure in gases
(b) liquid discharge
(c) pressure in liquids
(d) gas velocities
(e) temperature.
Ans: d

187. Rotameter is a device used to measure
(a) absolute pressure
(b) velocity of fluid
(c) flow
(d) rotation
(e) velocity of air.
Ans: c

18 Flow of water in a pipe about 3 metres in diameter can be measured by
(a) orifice plate
(b) venturi
(c) rotameter
(d) pitot tube
(e) nozzle
Ans: d

189. True one-dimensional flow occurs when
(a) the direction and magnitude of the veiocity at all points are identical
(b) the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time
(c) the magnitude and direction of the velocity do not change from point to point in the fluid
(d) the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane
(e) velocity, depth, pressure etc. change from point to point in the fluid flow.
Ans: a

190. An ideal flow of any fluid must satisfy
(a) Pascal law
(b) Newton's law of viscosity
(c) boundary layer theory
(d) continuity equation
(e) Bernoulli's theorem.
Ans: d

191. In the case of steady flow of a fluid, the acceleration of any fluid particle is
(a) constant
(b) variable
(c) zero
(d) zero under limiting conditions
(e) never zero.
Ans: c

193. Non uniform flow occurs when
(a) the direction and magnitude of the velocity at all points are identical
(b) the velocity of successive fluid particles, at any point, is the same at successive periods of time
(c) the magnitude aricf direction of the velocity do not change from point to point in the fluid
(d) the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane
(e) velocity, depth, pressure, etc. change from point to point in the fluid flow.
Ans: e

194. During the opening of a valve in a pipe line, the flow is
(c) uniform
(d) laminar
(e) free vortex type.
Ans: b

195. Uniform flow occurs when
(a) the flow is steady
(b) the flow is streamline
(c) size and shape of the cross section in a particular length remain constant
(d) size and cross section change uniformly along length
(e) flow occurs at constant fate.
Ans: c

196. Gradually varied flow is
(e) true one-dimensional.
Ans: d

197. Steady flow occurs when
(a) the direction and magnitude of the velocity at all points are identical
(b) the velocity of successive fluid particles, at any point, is the same at successive periods of time
(c) the magnitude and direction of the velocity do not change from point to point in the fluid
(d) the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane
(e) velocity, depth, pressure, etc. change from point to point in the fluid flow.
Ans: b

198. The flow which neglects changes in a transverse direction is known as
(a) one dimensional flow
(b) uniform flow
(d) turbulent flow
(e) streamline flow.
Ans: a

199. The flow in which each liquid particle has a definite path and their paths do not cross each other is called
(a) one dimensional flow
(b) uniform flow
(d) turbulent flow
(e) streamline flow.
Ans: e

200. The flow in which conditions do not change with time at any point, is known as
(a) one dimensional flow
(b) uniform flow
(d) turbulent flow
(e) streamline flow.
Ans: c

201. The flow in which the velocity vector is identical in magnitude and direction at every point, for any given instant, is known as
(a) one dimensional flow
(b) uniform flow
(d) turbulent flow
(e) streamline flow.
Ans: b

202. The flow in which the particles of a fluid attain such velocities that vary from point to point in magnitude and direction as well as from instant to instant, is known as
(a) one dimensional flow
(b) uniform flow
(d) turbulent flow
(e) streamline flow.
Ans: d

210. Flow occurring in a pipeline when a valve is being opened is
(c) laminar
(d) vortex
(e) rotational.
Ans: b

211. General energy equation holds for
(b) turbulent flow
(c) laminar flow
(d) non-uniform flow
(e) all of the above.
Ans: d

212. A streamline is defined as the line
(a) parallel to central axis flow
(b) parallel to outer surface of pipe
(c) of equal yelocity in a flow
(d) along which the pressure drop is uniform
(e) which occurs in all flows.
Ans: c

213. Two dimensional flow occurs when
(a) the direction and magnitude of the velocity at all points are identical
(b) the velocity of successive fluid particles, at any point, is the same at successive periods of time
(c) the magnitude and direction of the velocity do not change from point to point in the fluid
(d) the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane
(e) velocity, depth, pressure, etc. change from point to point in the fluid flow.
Ans: d

215. A piece of metal of specific gravity 7 floats in mercury of specific gravity 13.6. What fraction of its volume is under mercury ?
(a) 0.5
(b) 0.4
(c) 0.515
(d) 0.5
(e) none of the above.
Ans: c

216. A piece of wood having weight 5 kg floats in water with 60% of its volume under the liquid. The specific gravity of wood is
(a) 0.83
(b) 0.6
(c) 0.4
(d) 0.3
(e) none of the above.
Ans: b

218. The velocity of jet of water travelling out of opening in a tank filled with water is proportional to
(a) head of water (h)
(b) h2
(c) V/T
(d) h2
(e) h3/1.
Ans: c

219. In a free vortex motion, the radial component of velocity everywhere is
(a) maximum
(b) minimum
(c) zero
(d) non-zero and finite
(e) unpredictable.
Ans: c

220. In a forced vortex, the velocity of flow everywhere within the fluid is
(a) maximum
(b) minimum
(c) zero
(d) non-zero finite
(e) unpredictable.
Ans: d

221. The region between the separation streamline and the boundary surface of the solid body is known as
(a) wake
(b) drag
(c) lift
(d) boundary layer
(e) aerofoil section.
Ans: a

222. For hypersonic flow, the Mach number is
(a) unity
(b) greater than unity
(c) greater than 2
(d) greater than 4
(e) greater than 10.
Ans: d

223. The upper surface of a weir over which water flows is known is
(a) crest
(b) nappe
(c) sill
(d) weir top
(e) contracta.
Ans: c

224. Normal depth in open channel flow is the depth of flow corresponding to
(c) laminar flow
(d) uniform flow
(e) critical flow.
Ans: d

226. Uniform flow occurs when
(a) the direction and magnitude of the velocity at all points are identical
(b) the velocity of successive fluid paiticles, at any point, is the same at successive periods of time
(c) the magnitude and direction of the velocity do not change from point to point in the fluid
(d) the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each pleasure
(e) velocity, depth, pressure, etc. change from point to point in the fluid flow.
Ans: c

227. Pitot tube is used for measurement of
(a) pressure
(b) flow
(c) velocity
(d) dsscharge
(e) viscosity.
Ans: c

22 Hydrometer is used to determine
(a) specific gravity of liquids
(b) specific gravity of solids
(c) specific gravity of gases
(d) relative humidity
(e) density.
Ans: a

229. The total energy of each particle at various places in the case of perfect incompres sible fluid flowing in continuous sream
(d) keeps on increasing
(b) keeps on decreasing
(c) remains constant
(d) may increase/decrease
(e) unpredictable.
Ans: c

230. According to Bernoulli's equation for steady ideal fluid flow
(a) principle of conservation of mass holds
(b) velocity and pressure are inversely proportional
(c) total energy is constant throughout
(d) the energy is constant along a stream-line but may vary across streamlines
(e) none of the above.
Ans: d

231. The  equation of continuity holds good when the flow
(b) is one dimensional
(c) velocity is uniform at all the cross sections
(d) all of the above
(e) none of the above.
Ans: d

232. Mach number is significant in
(a) supersonics, as with projectiles and jet propulsion
(b) full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.
(c) simultaneous motion through two fluids where there is a surface of dis-continuity, gravity force, and wave making effects, as with ship's hulls
(d) all of fhe above
(e) none of the above.
Ans: a

233. Froude number is significant in
(a) supersonics, as with projectile and jet propulsion
(b) full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.
(c) simultaneous motion through two fluids where there is a surface of dis-continuity, gravity forces, and wave making effect, as with ship's hulls
(d) all of the above
(e) none of the above
Ans: c

234. All the terms of energy in Bernoulli's equation have dimension of
(a) energy
(b) work
(c) mass
(d) length
(e) time.
Ans: d

235. Reynolds number is significant in
(a) supersonics, as with projectile and jet propulsion
(b) full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.
(c) simultaneous motion through two fluids where there is a surface of dis-continuity, gravity forces, and wave making effect, as with ship's hulls
(d) all of the above
(e) none of the above.
Ans: b

236.  The fluid forces considered in the Navier Stokes equation are
(a) gravity, pressure and viscous
(b) gravity, pressure and turbulent
(c) pressure, viscous and turbulent
(d) gravity, viscous and turbulent
(e) none of the above.
Ans: a

237. A large Reynold number is indication of
(a) smooth and streamline flow
(b) laminar flow
(d) turbulent flow
(e) highly turbulent flow.
Ans: e

239. For pipes, laminar flow occurs when Roynolds number is
(a) less than 2000
(b) between 2000 and 4000
(c) more than 4000
(d) less than 4000
(e) none of the above.
Ans: a

240. In order that flow takes place between two points in a pipeline, the differential pressure between these points must be more than
(a) frictional force
(b) viscosity
(c) surface friction
(d) all of the above
(e) none of the above.
Ans: d

241. At the center line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be
(a) minimum
(b) maximum
(c) zero
(d) negative value
(e) could be any value.
Ans: e

242. The pressure in Pascals at a depth of 1 m below the free surface of a body of water will be equal to
(a) 1 Pa
(b) 91 Pa
(c) 981 Pa
(d) 9810 Pa
(e) 98,100 Pa.
Ans: d

244. Two pipe systems can be said to be equivalent, when the following quantites are same
(a) friction loss and flow
(b) length and diameter
(c) flow and length
(d) friction factor and diameter
(e) velocity and diameter.
Ans: a

245. For pipes, turbulent flow occurs when Reynolds number is
(a) less than 2000
(b) between 2000 and 4000
(c). more than 4000
(d) less than 4000
(e) none of the above.
Ans: c

246. Bernoulli equation deals with the law of conservation of
(a) mass
(b) momentum
(c) energy
(d) work
(e) force.
Ans: c

247. A hydraulic press has a ram of 15 cm diameter and plunger of 1.5 cm. It is required to lift a weight of 1 tonne. The force required on plunger is equal to
(a) 10 kg
(b) 100 kg
(c) 1000 kg
(d) 1 kg
(e) 10,000 kg.
Ans: a

248. Cavitation is caused by
(a) high velocity
(b) high pressure
(c) weak material
(d) low pressure
(e) low viscosity.
Ans: d

249. Cavitation will begin when
(a) the pressure at any location reaches an absolute pressure equal to the         saturated vapour pressure of the liquid
(b) pressure becomes more than critical pressure
(c) flow is increased
(d) pressure is increased
(e) none of the above.
Ans: a

250. Principle of similitude forms the basis of
(a) comparing two identical equipments
(b) designing models so that the result can be converted to prototypes
(c) comparing similarity between design and actual equipment
(d) hydraulic designs
(e) performing acceptance tests.
Ans: b

251. For similarity, in addition to models being geometrically similar to prototype, the following in both cases should also be equal
(a) ratio of inertial force to force due to viscosity
(b) ratio of inertial force to force due to gravitation
(c) ratio of inertial force to force due to surface tension
(d) all the four ratios of inertial force to force due to viscosity, gravitation, sur-face tension, and elasticity
Ans: d

Frequently asked Multiple Choice Questions

GAS DYNAMICS

1. Free air is the air at:
(a) atmospheric conditions at any specific location
(b) 20°C and 1 kg/cm2 and relative humidity of 36%
(c) 0°C and standard atmospheric conditions
(d) 15°C and 1 kg/cm2
(e)  25°C, 1 kg/cm2 and relative humidity of 50%.
Ans: a

2. Standard air is the air at
(a) atmospheric conditions at any specific location
(b) 20°C and 1 kg/cm2 and relative humidity 36%
(c) 0°C and standard atmospheric conditions
(d) 15°C and 1 kg/cm2
(e) 25°C, 1 kg/cm2 and RH of 60%.
Ans: b

3. 1 m of air at atmospheric condition weighs approximately
(a) 0.5 kg
(b) 1.0 kg
(c) 1.3 kg
(d) 2.2 kg
(e) 3.2 kg.
Ans: c

4. Adiabatic compression is one in which
(a) temperature during compression remains constant
(b) no heat leaves or enters the compressor cylinder during cornpression
(c) temperature rise follows a linear relationship
(d) work done is maximum
(e) entropy decreases.
Ans: b

5. The capacity of a compressor is 5 m /mih. 5 m /min refers to
(a) standard air
(b) free air
(c) compressed air
(d) compressed air at delivery pressure
(e) air sucked.
Ans: b

6. The overall isothermal eiffciency of compressor is defined as the ratio of
(a) isothermal h.p. to the BHP of motor
(b) isothermal h.p. to adiabatic h.p.
(c) power to drive compressor to isothermal h.p.
(d) work to compress air isothermally to work for actual compression
(e) isothermal work to ideal work.
Ans: a

7. The- most efficient method of compressing air is to compress it
(a) isothermally
(c) isentropically
(d) isochronically
(e) as per law pV
Ans: a

8. Maximum work is done in compressing air when the compression is
(a) isothermal
(c) polytropic
(d) any one of the above
(e) none of the above.
Ans: b

9. The pressure and temperature conditions of air at the suction of compressor are
(a) atmospheric
(b) slightly more than atmospheric
(c) slightly less than atmospheric
(d) pressure slightly more than atmospheric and temperature slightly less than atmospheric
(e) pressure sightly less than atmospheric and temperature slightly more than atmospheric.
Ans: e

10. Isothermal compression effeicency can be attained by running the compressor
(a) at very high speed
(b) at very slow speed
(c) at average speed
(d) at zero speed
(e) isothermally.
Ans: b

11. The compressor capacity with decrease in suction temperature
(a) increases
(b) decreases
(c) remains unaffected
(d) may increase or decrease depending on compressor capacity
(e) increases upto certain limit and then decreases.
Ans: a

12. Isothermal compression efficiency, even when running at high speed, can be approached by using
(a) multi-stage compression
(b) cold water spray
(c) both (a) and (b) above
(d) fully insulating the cylinder
(e) high stroke.
Ans: c

13. Compression efficiency is compared against
(a) ideal compression
(c) botii isothermal and adiabatic compression
(d) isentropic compression
(e) isothermal compression.
Ans: e

14. Aeroplanes employ following type of compressor
(b) axial flow
(c) centrifugal
(d) combination of above
(e) none of the above.
Ans: b

15. Inter cooling in compressors
(a) cools the delivered air
(b) results in saving of power in compressing a given volume to given pressure
(c) is the standard practice for big compressors
(d) enables compression in two stages
(e) prevents   compressor  jacket   running very hot.
Ans: b

16. An ideal air compressor cycle without clearance on p-v diagram can be represented by following processes
(a) one adiabatic, two isobaric, and one constant volume
(b) two adiabatic and two isobaric
(c) two adiabatic, one isobaric and one constant volume
(d) one adiabatic,  one  isobaric  and two constant volume
(e) two isobaric,  two adiabatic and one constant volume.
Ans: a

17. An ideal air compressor cycle with clearance on p-v diagram can be represented by following processes
(a) one adiabatic, two isobaric, and one constant volume
(b) two adiabatic and two isobaric
(c) two adiabatic,  one  isobaric  and  one constant volume,
(d) one adiabatic, one isobaric and two constant volume
(e) two  isobaric,  two adiabatic and one constant volume.
Ans: b

18. What will be the volume of air at 327°C if its volume at 27°C is 1.5 m3/mt
(a)  3 m3/mt .
(b)  1.5 m3/mt
(c)  18 m3/mt'
(d)  6 m3/mt
(e)  0.75 m3/mt.
Ans: a

19. The work done per unit mass of air in compression will'be least when n is equal to
(a) 1
(b) 1.2     ,
(c) 1.3
(d) 1.4
(e) 1.5
Ans: a

20. Isothermal compression though most efficient, but is not -practicable because
(a) ityrequires very big cylinder
(b) it does not increase pressure much
(c) it is impossible in practice
(d) compressor has to  run  at  very  slow speed to achieve it
(e) it requires cylinder to be placed in water.
Ans: d

21. Ratio of indicated H.P. and brake H.P. is known as
(a) mechanical efficiency
(b) volumetric efficiency
(c) isothermal efficiency
(e) relative efficiency.
Ans: a

22. The ratio of work doen per cycle to the swept volume in case of compressor is called
(a) compression index
(b) compression ratio
(c) compressor efficiency
(d) mean effective pressure
(e) compressor effectiveness.
Ans: d

23. Cylinder clearance in a compressor should be
(a) as large as possible
(b) as small as possible
(c) about 50% of swept volume
(d) about 100% of swept volume
(e) none of the above.
Ans: b

24. Ratio of compression is the ratio of
(a) gauge discharge pressure to the gauge intake pressure
(b) absolute discharge pressure to the ab-solute intake pressure
(c) pressures at discharge and suction cor-responding to same temperature
(d) stroke volume and clearance volume
(e) none of the above.
Ans: b

25. Clearance volume in actual reciprocating compressors is essential
(a) to accommedate Valves in the cylinder head
(b) to provide cushioning effect
(c) to attain high volumetric efficiency
(d) to avoid mechanical bang of piston with cylinder head
(e) to provide cushioning effect and also to avoid mechanical bang of piston with cylinder head.
Ans: e

26. The net work input required for compressor with increase in clearance volume
(a) increases
(b) decreases
(c) remains same
(d) increases/decreases depending on com-pressor capacity
(e) unpredictable.
Ans: c

27. Ratio of indicated h.p. to shaft h.p. in known as
(a) compressor efficiency
(b) isothermal efficiency
(c) volumetric efficiency
(d) mechanical efficiency
Ans: d

28. Volumetric efficiency is
(a) the ratio of stroke volume to clearance volume
(b) the ratio of the air actually delivered to the amount of piston displacement
(c) reciprocal of compression ratio
(d) index of compressor performance
(e) proportional to compression ratio.
Ans: b

29. Volumetric efficiency of air compressors is of the order of
(a) 20-30%
(b) 40-50%
(c) 60-70%
(d) 70-90%
(e) 90-100%.
Ans: d

30. Volumetric efficiency of a compressor with clearance volume
(a) increases with increase in compression ratio
(b) decreases with increase in compression ratio
(c) in  not  dependent  upon  compression ratio
(d) may  increase/decrease depending  on compressor capacity
(e) unpredictable.
Ans: b

31. Volumetric efficiency of a compressor without clearance volume
(a) increases with increase in compression ratio
(b) decreases with increase in compression ratio
(c) is not dependent upon compressin ratio
(d) may  increase/decrease  depending  on compressor capacity
(e) unpredictable.
Ans: c

32. The clearance volume of the air compressor is kept minimum because
(a) it allows maximum compression to be achieved
(b) it greatly affects volumetric efficiency
(c) it results in minimum work
(d) it permits isothermal compression
(e) none of the above.
Ans: b

33. Euler's equation is applicable for
(a) centrifugal compressor
(b) axial compressor
(c) pumps
(d) all of the above
(e) none of the above.
Ans: d

40. Out of the following, from where you will prefer to take intake for air compressor
(a) from an air conditioned room maintained at 20°C
(b) from outside atmosphere at 1°C
(c) from coal yard side
(d) from a side where cooling tower is located nearby
(e) from any one of the above locations.
Ans: d

41. Mining industry usually employs following motive power
(a) A.C. electric motor
(b) compressed air
(c) petrol engine
(d) diesel engine
(e) D.C. electric motor.
Ans: b

42. Which is false statement about air receivers
(a) These are used to dampen pulsations ,
(b) These act as reservoir to- take care of sudden demands
(c) These increase compressor efficiency
(d) These knock out some oil and moisture
(e) These reduce frequent on/off operation of compressors.
Ans: c

44. An air receiver is to be placed outside. Should it be placed in
(a) sun
(c) rain
(d) enclosed room
(e) anywhere.
Ans:

45. Which is false statement about multistage compression .
(a) Power consumption per unit of air delivered is low
(b) Volumetric efficiency is high
(c) It is best suited for compression ratios around 7:1
(d) The moisture in air is condensed in the intercooler
(e) Outlet temperature is reduced.
Ans: b

46. In multistage compressor, the isothermal compression is achieved by
(a) employing intercooler
(b) by constantly cooling the cylinder
(c) by running compressor at very slow speed
(d) by insulating the cylinder
(e) none of the above.
Ans: c

47. Reciprocating air compressor is best suited for
(a) large quantity of air at high pressure
(b) small quantity of air at high pressure
(c) small quantity of air at low pressure
(d) large quantity of air at low pressure
(e) any one of the above.
Ans: a

48. Rotary compressor is best suited for
(a) large quantity of air at high pressure
(b) small quantity of air at high pressure
(c) small quantity of air at low pressure
(d) large quantity of air at low pressure
(e) any one of the above.
Ans: b

49. The capacity of compressor will be highest when its intake temperature is
(a) lowest
(b) highest
(c) anything.
(d) atmospheric
(e) none of the above.
Ans: d

50. After-cooler is used to
(a) cool the air
(b) decrease the delivery temperature for ease in handling
(c) cause moisture and oil vapour to drop out
(d) reduce volume
(e) increase pressure.
Ans: c

51. To aviod moisture troubles, the compressed air main line should
(a) rise gradually towards the point of use
(b) drop gradually towards the point of use
(c) be laid vertically
(d) be laid exactly horizontally
(e) none of the above
Ans: b

52. Separators in compressor installations are located
(a) before intercooler
(b) after intercooler
(d) between after-cooler and air receiver
(e) before suction.
Ans: d

53. The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is
(a) less
(b) more
(c) same
(d) more/less depending on compressor capacity
(e) unpredictable.
Ans: b

54. An air compressor may be controlled by
(a) throttle control (b) clearance control
(c) blow-off control
(d) any one of the above
(e) none of the above.
Ans: d

55. The compressor efficiecny is the
(a) isothermal H.P/indicated H.R
(b) isothermal H.P./shaft H.R
(c) total output/air input
(d) compression work/motor input
(e) none Of the above.
Ans: a

56. To avoid moisture troubles, the branch connections from compressed air lines should be taken from
(a) top side of main
(b) bottom side of main
(c) left side of main
(d) right side of main
(e) any location.
Ans: a

57. The thrust on the rotor in a centrifugal compressor is produced by
(b) axial component
(c) tangential component
(d) resultant component
Ans: b

58. The compressor performance at higher altitude compared to sea level will be
(a) same
(b) higher
(c) lower
(d) dependent on other factors
(e) none of the above.
Ans: c

59. A compressor at high altitude will draw
(a) more power
(b) less power
(c) same power
(d) more/less power depending on other factors
(e) none of the above.
Ans: b

60. During peak load periods, the best method of controlling compressors is
(a) start-stop motor
(b) constant speed unloader
(c) relief valve
(d) variable speed
(e) none of the above.
Ans: b

61. A centrifugal compressor works on the principle of
(a) conversion   of  pressure   energy   into kinetic energy
(b) conversion of kinetic energy into pres¬sure energy
(c) centripetal action
(d) generating pressure directly
(e) combination of (a) and (d).
Ans: b

62. For a compressor, least work will be done if the compression is
(a) isentropic
(b) isothermal
(c) polytropic
(d) somewhere in between isentropic and isothermal
(e) none of the above.
Ans: b

67. In a compressor, free air delivered is the actual volume delivered at the stated pressure reduced to
(d) N.T.P. conditions
(b) intake temperature and pressure conditions
(c) 0°C and 1 kg/cm2
(d) 20°C and 1 kg/cm2
(e) none of the above.
Ans: b

68. The volumetirc efficiency of a compressor is calculated on the basis of
(a) volume of air inhaled at working conditions
(b) volume of air inhaled at N.T.P. conditions
(c) volume at 0°C and 1 kg/cm2
(d) volume at 20°C and 1 kg/cm2
(e) none of the above.
Ans: b

69. The volumetric efficiency of a compressor falls roughly as follows for every 100 m increase in elevation
(a) 0.1%
(b) 0.5%
(c) 1.0%
(d) 5%
(e) 10%.
Ans: c

70. For slow-speed large capacity compressor, following type of valve will be best suited
(a) poppet valve
(b) mechanical valve of the corliss, sleeve, rotary or semirotary type
(c) disc or feather type
(d) any of the above
(e) none of the above.
Ans: c

71. During base load operation, the best method of controlling compressor is
(a) start-stop motor
(b) constant speed unloader
(c) relief valve
(d) variable speed
(e) none of the above.
Ans: a

72. More than one stage will be preferred for reciprocating compressor if the delivery pressure is more than
(a) 2 kg/cm2
(b) 6 kg/cm2
(c) 10 kg/cm2
(d) 14.7 kg/cm2
(e) none of the above.
Ans: a

73. The advantage of multistage compression over single stage compression is
(a) lower power consumption per unit of air delivered
(b) higher volumetric efficiency
(c) decreased discharge temperature
(d) moisture free air
(e)     all of the above.
Ans: e

74. Pick up the wrong statement about advantages of multistage compression
(a) better lubrication is possible advantages of multistage
(b) more loss of air due to leakage past the cylinder
(c) mechanical balance is better
(d) air can be cooled perfectly in between
(e) more uniform torque, light cylinder and saving in work.
Ans: b

75. As the value of index '«' is decreased, the volumetric efficiency will
(a) increase
(b) decrease
(c) remain unaffected
(d) may  increase/decrease  depending  on compressor clearance
(e) none of the above.
Ans: b

76. The ratio of outlet whirl velocity to blade velocity in case of centrifugal compressor is called
(a) slip factor
(b) velocity factor
(c) velocity coefficient
Ans: a

79. Losses in a centrifugal compressor are due to
(a) inlet losses
(b) impeller channel losses
(c) diffuser losses
(d) all of the above
(e) none of the above
Ans: d

80. The volumetric efficiency of a compressor falls roughly as follows for every 5°C increase in atmospheric temperature
(a) 0.1%
(b) 0.5%
(c) 1%
(d) 5%
(e ) 10%.
Ans: c

81. The indicated work per unit mass of air delivered is
(a) directly proportional to clearance volume
(b) greatly affected by clearance volume
(c) not affected by clearance volume
(d) inversely proportional to clearance volume
Ans: c

89. For actual single stage centrifugal compressor, the maximum pressure ratio is of the order of
(a) 1 : 1.2
(b) 1 : 2
(c) 1 : 4
(d) 1 : 10
(e) 1 : 1
Ans:

90. Which is false statement about advantages of multistage compressor in comparison to single stage compressor
(a) less power requirement
(b) better mechanical balance
(c) less loss of air due to leakage past the cylinder
(d) more effective lubrication
(e) lower volumetric efficiency.
Ans: e

91. The ratio of isentropic work to Euler work is known as
(a) pressure coefficient
(b) work coefficient
(c) polytropic reaction
(d) slip factor
(e) compressor efficiency.
Ans: a

92. The criterion of the thermodynamic efficiency for rotary compressor is
(a) isentropic compression
(b) isothermal compression
(c) polytropic compression
(d) any one of the above
(e) none of the above.
Ans: a

93. For supplying intermittent small quantity of air at high pressure, following compressor is best suited
(a) centrifugal
(b) reciprocating
(c) axial
(d) screw
(e) turbo jet.
Ans: b

94. For minimum work in multistage compression, assuming same index of compression in all stages
(a) work done in first stage should be more
(b) work done in subsequent stages should increase
(c) work done in subsequent stages should decrease
(d) work done in all stages should be equal
(e) work done in any stage is no criterion for minimum work but depends on other factors.
Ans: d

95. For a two stage compressor* if index of compression for higher stage is greater than index of compression for lower stage, then the optimum pressure as compared to ideal case will
(a) increase
(b) decrease
(c) remain unaffected
(d) other factors control it
(e) unpredictable.
Ans: a

96. Diffuser in a compressor is used to
(a) increase velocity
(b) make the flow stream-line
(c) convert pressure energy into kinetic energy
(d) convert kinetic energy into pressure energy
(e) increase degree of reaction.
Ans: d

98. The ratio of isentropic work to euler's work is known as
(a) compressor efficiency
(b) isentropic efficiency
(c) Euler's efficiency
(d) pressure coefficient
(e) pressure ratio.
Ans: d

99. The thermodynamic efficiency of rotary compressor is based on
(a) isothermal compression
(c) isentropic compression
(d) polytropic compression
(e) none of the above.
Ans: b

100. Phenomenon of choking in compressor means
(a)     no flow of air
(b) fixed mass flow rate regardless of pressure ratio
(c) reducing mass flow rate with increase in pressure ratio
(d) increased inclination of chord with air steam
(e) does not occur.
Ans: b

101. The maximum compression ratio in an actual single stage axial flow comperssor is of the order of
(a) 1 : 1.2
(b) 1 : 2
(c) 1 : 5
(d) 1 : 10
(e) 1 : 1
Ans: a

102. Maximum delivery pressure is a rotary air compressor is of the order of
(a) 6 kg/cm2
(b) 10 kg/cm2
(c) 16 kg/cm2
(d) 25 kg/cm2
(e) 40 kg/cm2.
Ans: b

103. Surging is the phenomenon of
(a) air stream blocking the passage
(b) motion of air at sonic velocity
(c) unsteady, periodic and reversed flow
(d) air stream not able to follow the blade contour
(e) production of no air pressure.
Ans: c

104. Pick up wrong statement.
Surging phenomenon in centrifugal com-pressor depends on
(a) mass flow rate
(b) pressure ratio
(c) change in load
(d) stagnation pressure at the outlet
(e) all of the above.
Ans: d

105. The ratio of the increase in pressure in rotor blades to total increase in pressure in the stage is called
(a) pressure ratio
(b) pressure coefficient
(c) degree of reaction
(d) slip factor
(e)     stage factor.
Ans: c

106. Axial flow compressor resembles
(a) centrifugal pump
(b) reciprocating pump
(c) turbine
(d) sliding vane compressor
(e) none of the above.
Ans: c

107. Axial flow compressor has the following advantage over centrifugal compressor
(a)     larger air handling  ability  per  unit frontal area
(b)     higher pressure ratio per stage
(c) aerofoil blades are used
(d) higher average velocities
(e) none of the above.
Ans: a

108. Actual compression curve is
(a) same as isothermal
(b) same as adiabatic
(c) better than isothermal and adiabatic
(d) in between isothermal and adiabatic
(e) none of the above.
Ans: d

109. Atmospheric pressure is 1.03 kg/cm and vapour pressure is 0.03 kg/cm . The air pressure will be
(a) 1.03 kg/cm2
(b) 1.06 kg/cm2
(c) 1.00 kg/cm2
(d) 0.53 kg/cm2
(e) 0.5 kg/cm2.
Ans: c

110. The pressure ratio of an ideal vaned compressor with increase in mass flow rate
(a) increases
(b) decreases
(c) remains constant
(d) first decreases and then increases
(e) unpredictable.
Ans: c

111. Rotary compressors are suitable for
(a) large discharge at high pressure
(b) low discharge at high pressure
(c) large discharge at low pressure
(d) low discharge at low pressure
(e) there is no such limitation.
Ans: c

112. The vloumetric efficiency of compressor with increase in compression ratio will
(a) increase
(b) decrease
(c) remain same
(d) may increase/decrease depending on clearance volume
(e) none of the above.
Ans: b

113. Stalling of blades in axial flow compressor is the phenomenon of
(a) air stream blocking the passage
(b) motion of air at sonic velocity
(c) unsteady periodic and reversed flow
(d) air stream not able to follow the blade contour
(e) production of no air pressure.
Ans: d

114. Pick up the wrong statement
(a)     centrifugal compressors deliver prac-tically constant pressure over a considerable range of capacities
(b)     Axial flow compressors have a sub-stantially constant delivery at variable pressures
(c) centrifugal compressors have a wider stable operating range than axial flow compressors
(d) axial flow compressors are bigger in diameter compared to centrifugal type
(e) axial flow compressors apt to be longer as compared to centrifugal type.
Ans: d

115. The work ratio of a gas turbine plant is defined as the ratio of
(a) net work output and heat supplied

(b) net work output and work done by turbine
(c) actual heat drop and isentropic heat drop
(d) net work output and isentropic heat drop
(e) isentropic increase/drop in tempera¬ture and actual increase/ drop in temperature.
Ans: b

116. Gas turbine works on
(a) Brayton or Atkinson cycle
(b) Carnot cycle
(c) Rankine cycle
(d) Erricsson cycle
(e) Joule cycle.
Ans: a

117. The work ratio of simple gas turbine cycle depends on
(a) pressure ratio
(b) maximum cycle temperature
(c) minimum cycle temperature
(d) all of the above
(e) none of die above.
Ans: d

118. The pressure ratio for an open cycle gas turbine compared to closed cycle gas turbine of same h.p. is
(a) low
(b) high
(c) same
(d) low/high depending on make and type
(e) unpredictable.
Ans: a

119. Open cycle gas turbine works on
(a) Brayton or Atkinson cycle
(6) Rankine cycle
(c) Carnot cycle
(d) Erricsson cycle
(e) Joule cycle.
Ans: a

120.  The fuel consumption in gas turbines is accounted for by
(a) low.er heating value
(b) higher heating value
(c) heating value
(d) higher calorific value
(e) highest calorific value.
Ans: a

121. Gas turbines for power generaion are normally used
(a) to supply base load requirements
(b) to supply peak load requirements
(c) to enable start thermal power plant
(d) in emergency
(e) when other sources of power fail.
Ans: b

122. Mechanical efficiency of gas turbines as compared to I.C engines is
(a) higher
(b) lower
(c) same
(d) depends on on odier considerations
(e) unpredictable.
Ans: a

123. The ratio of specific weighf/h.p. of gas turbin and I.C engines may be typically of the order of
(a) 1 : 1
(b) 2 : 1
(c) 4 : 1
(d) 1 : 2
(e) 1 : 6
Ans: e

124. The thermal efficiency of a gas turbine as compared to a diesel plant is
(a) same
(b) more
(c) less
(d) depends on other factors
(e) unpredictably.
Ans: c

125. The air-fuel ratio in gas turbines is of the order of
(a) 7 : 1
(b) 15 : 1
(c) 30 : 1
(d) 40 : 1
(e) 50 : 1
Ans: e

126. The pressure ratio in gas turbines is of the order of
(a) 2:l
(b) 4:1
(c) 61: 1
(d) 9 : 1
(e) 12:1.
Ans: c

128. The hottest point in a gas turbine is
(a) at the base
(b) at the tip
(c) in the center
(d) between root to tip of the blade height
(e) uniformly heated.
Ans: d

129. The following is true for an open cycle gas turbine having exhaust heat exchanger. Atmospheric air before entering the compressor is
(a) heated
(b) compressed air before entering the combustion chamber is heated
(c) bled gas from turbine is heated and readmitted for complete expansion
(d) exhaust gases drive the compressor
(e) part of exhaust gases are heated and mixed up with atmospheric air to utilise exhaust heat.
Ans: b

130. Gas turbine blades are given a rake
(a) equal to zero
(b) in the direction of motion of blades
(c) opposite to the direction of motion of blades
(d) depending on the velocity
(e) none of the above.
Ans: b

131. Efficiency of gas turbine is increased by
(a) reheating
(b) inter cooling
(c) adding a regenerator
(d) all of the above
(e) none of the above.
Ans: c

132. Temperature of gases at end of compression as compared to exhaust gases in a gas turbine is
(a) higher
(b) lower
(c) equal
(d) can't be compared
(e) unpredictable.
Ans: b

133. The ideal efficiency of simple gas turbine cycle depends on
(a) pressure ratio
(b) maximum cycle temperature
(c) minimum cycle temperature
(d) all of the above
(e) none of the above.
Ans: a

134. The thermal efficiency of a simple gas turbine for a given turbine inlet temperature with increase in pressure ratio
(a) increases
(b) decreases
(c) first increases and then decreases
(d) first decreases and then increases
(e) remains same.
Ans: a

135. Gas turbines use following type of air compressor
(a) centrifugal type
(b) reciprocating type
(c) lobe type
(d) axial flow type
(e) none of the above.
Ans: d

136. As the turbine inlet temperature increases, the thermal efficiency of gas turbine for the optimum pressure ratio
(a) increases
(b) decreases
(c) remains same
(d) first increases and then decreases
(e) first decreases and then increases.
Ans: a

137. There is a certain pressure ratio (optimum) for a gas turbine at which its thermal efficiency is maximum. With increase in turbine temperature, the value of pressure ratio for the peak efficiency would
(a) remain same
(b) decrease
(c) increase
(d) unpredictable
(e) none of the above.
Ans: c

138. The material commonly used for air craft gas turbine is
(a) stainless steel
(b) high alloy steel
(c) duralumin
(d) Timken, Haste and Inconel allpys
(e) titanium.
Ans: d

139. It is not possible to use closed gas turbine cycle in aeronautical engines because
(a) it is inefficient
(b) it is bulky
(c) it requires cooling water for its operation
Ans: c

140. The combustion efficiency of a gas turbine using perfect combustion chamber is of the order of
(a) 50%
(b) 75%
(c) 85%
(d) 90%
(e ) 99%.
Ans: e

141. The maximum combustion pressure in gas turbine as compared to I.C. engine is
(a) more
(b) less
(c) same
(d) depends on other factors
(e) unpredictable.
Ans: b

142. For an irreversible gas turbine cycle, the efficiency and work ratio both depend on
(a) pressure ratio alone
(b) maximum cycle temperature alone
(c) minimum cycle temperature alone
(d) both pressure ratio and maximum cycle temperature
(e) none of the above.
Ans: d

143. Producer gas is produced by
(a) carbonisation of coal
(b) passing steam over incandescent coke
(c) passing air and a large amount of steam over waste coal at about 65°C
(d) partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
(e) same way as the natural gas.
Ans: d

144. Water gas is produced by
(a) carbonisation of coal
(b) passing steam over incandescent coke
(c) passing air and a large amount of steam over waste coal at about 65°C
(d) partial combustion of caol, eke, anthractie coal or charcoal in a mixed air steam blast
(e) same way as the natural gas.
Ans: b

14 Water is injected in gas turbine cycle to
(a) control temperature
(b) control output of turbine
(c) control fire hazards
(d) increase efficiency
(e) it is never done.
Ans: b

146. A gas turbine used in air craft should have
(a) high h.p. and low weight
(b) low weight and small frontal area
(c) small frontal area and high h.p.
(d) high speed and high h.p.
(e) all of the above.
Ans: b

148. The closed cycle in gas turbines
(a) provides greater flexibility
(b) provides lesser flexibility
(c) in never used
(d) is used when gas is to be burnt
(e) none of the above.
Ans: a

149. In the axial flow gas turbine, the work ratio is the ratio of
(a) compressor work and turbine work
(b) output and input
(c) actual total head tempeature drop to the isentrpic total head drop from total head inlet to static head outlet
(d) actual compressor work and theoretical comprssor work
(e) none of the above.
Ans: c

150. The degree of reaction of an axial flow turbine is the ratio of isentropic temperature drop in a blade row to the
(a) adiabatic temperature drop in the stage
(b) total temperature drop
(c) total temperature drop in the stage
(d) total adiabaitc temperature drop
(e) difference of maximum and minimum temperature in the cycle.
Ans: c

153. If infinite number of heaters be used in a gas turbine, then expansion process in turbine approaches
(a) isothermal
(b) isentropic
(d) isochoric
(e) isobaric.
Ans: a

154. Pick up the correct statement
(a) gas turbine uses low air-fuel ratio to economise on fuel
(b) gas turhine uses high air-fuel ratio to reduce outgoing temperature
(c) gas turbine uses low air-fuel ratio to develop the high thrust required
(d) all of the above
(e) none of the above.
Ans: b

15 Intercooling in gas turbine results in
(a) increase in net output but decrease in thermal efficiency
(b) increase   in   thermal  efficiency  but decrease in net output
(c) increase in both thermal efficiency and net output
(d) decrease in both thermal efficiency and net output
(e) none of the above.
Ans: a

156. If V, U and Vr represent the absolute velocity of fluid, velocity of blade, and relative velocity of fluid, and suffix i and o stand for entry and exit conditions, then in a rotary machine whose degree of reaction is unity
(a)Vi=V0
(b)Vt>V0
(c) U,<V0
(d)V,= U0
(e) Vri=Vm.
Ans: a

157. Pick up the wrong statement
(a) large gas turbines employ axial flow compressors
(b) axial flow compressors are more stable than centrifugal type compressors but not as efficient
(c) axial flow compressors have high capacity and efficiency
(d) axial   flow   compressors   have   instability region of operation
(e) centrifugal compressors are used mainly on low flow pressure ratio gas turbines.
Ans: b

158. The power available for take off and climb in case of turbojet engine as compared to reciprocating engine is
(a) less
(b) more
(c) same
(d) may be less or more depending on ambient conditons
(e) unpredictable.
Ans: a

159. Pick up the correct statement
(a) large gas turbines use radial inflow turbines
(b) gas turbines have their blades similar to steam turbine
(c) gas .turbine's blade will appear as impulse section at the hub and as a reaction section at tip
(d) gas turbines use both air and liquid cooling
(e) all of the above are correct.
Ans: c

160. A closed gas turbine in which fuel is burnt directly in the air is not possible because of
(a) high pressure ratio
(b) increasing gas temperature
(c) high specific volume
(d) high friction losses
(e) paucity of Oxygen.
Ans: e

161. Choose the correct statement
(a) gas turbine requires lot of cooling water
(b) gas turbine is capable of rapid start up and loading
(c) gas turbines have flat efficiency at part loads
(d) gas turbines have high standby losses and require lot of maintenance
(e) gas turbines can be used to generate power only.
Ans: b

162. Ram compression in turbojet involves
(a) reduction of speed of incoming air and conversion of part of it into pressure energy
(b) compression of inlet air
(c) increasing speed of incoming air
(d) lost work
(e) leakage losses.
Ans: a

163. In gas turbines high thermal efficiency is obtained in
(a) closed cycle
(b) open cycle
(c) both of the above
(d) closed/open depending on other con-siderations
(e) unpredictable.
Ans: a

164. In the cross compounding of the gas turbine plant
(a) h.p. compressor L connected to h.p. turbine and l.p. compressor ot l.p. tur-bine
(b) h.p. compressor is connected to l.p. turbine and l.p. compressor is con-nected to h.p. turbine
(c) both the arrangements can be employed
(d)  all are connected in series
(e) none of the above.
Ans: b

16 A jet engine works on the principle of conservation of
(a) mass
(b) energy
(c) flow
(d) linear momentum
(e) angular momentum.
Ans: d

166. In jet engines, for the efficient production of large power, fuel is burnt in an atmosphere of
(a) vacuum
(b) atmospheric air
(c) compressed air
(d) oxygen alone
(e) liquid hydrogen.
Ans: c

167. Which of the following fuels can be used in turbojet engines
(a) liquid hydrogne
(b) high speed diesel oil
(c) kerosene
(d) demethylated spirit
(e) methyl alcohol
Ans: c

168. Turbo propeller has the following additional feature over the turbojet
(a) peopeller
(b) diffuser
(c) intercooler
(d) turbine and combustion chamber
(e) starting engine.
Ans: a

169. Propulsive efficiency is defined as ratio of
(a) thrust power and fuel energy
(b) engine output and propulsive power
(c) propulsive power and fuel input
(d) thrust power and propulsive power
(e) none of the above.
Ans: d

170. In jet engines, paraffin is usually used as the fuel because of its
(a) high calorific value
(b) ease of atomisation
(c) low freezing point
(d) (a) and (c) above
(e) none of the above.
Ans: d

171. A rocket engine for the combustion of its fuel
(a) carries its own oxygen
(b) uses surrounding air
(c) uses compressed atmospheric air
(d) does not require oxygen
(e) depends on electrical energy supplied by solar cells.
Ans: a

172. A rocket works with maximum overall efficiency when air craft velocity is equal to the
(a) jet velocity
(b) twice the jet velocity
(c) half the jet velocity
(d) average of the jet velocity
(e) no such co-relationship with jet velocity exists.
Ans: c

173. Propulsion efficiency of the following order-is obtained in practice
(ti) 34%
(b) 50%
(c) 60%
(d) 72%
(e) 85%.
Ans: c

174. The maximum propulsion efficiency of a turbojet is attained at around following speed -
(a) 550 km/hr
(b) 1050km/hr
(c) 1700 km/hr
(d) 2400km /hr
(e) 4000 km/hr.
Ans: d

17 In jet propulsion power unit, the inlet duct of diverging shape is used in order to
(a) collect more air
(b) convert kinetic energy of air into pres-sure energy
(c) provide robust structure
(d) beautify the shape
(e) none of the above
Ans: b

176. In jet engines the products of combustion after passing through the gas lurbine are discharged into
(a) atmosphere
(b) back to the compressor
(c) discharge nozzle
(d) vacuum
(e) none of the above.
Ans: c

177. The air entry velocity m a rocket as compared to aircraft is
(a) same
(b) more
(c) less
(d) zero
(e) dependent on power and speed.
Ans: d

183. The weight per horse power ratio for gas. turbine as compared to I.C. engine and steam turbine is
(a) same
(b) higher
(c) lower
(d) uncomparable
(e) unpredictable.
Ans: c

184. Fighter bombers use following type of engine
(a) turbo-jet
(b) turbo-propeller
(c) rocket
(d) ram-jet ,
(e) pulsojet.
Ans: a

18 Pick up the wrong statement
(a) pulsojet requires no ambient air for propulsion
(b) ramjet-engine has no turbine
(c) turbine drives compressor in a burbojet
(d) bypass turbo-jet engine increases the thrust without adversely affecting, the propulsive efficiency and fuel economy
(e) propeller is an indirect reaction device.
Ans: a

186. Thrust of a jet propulsion power unit can be increased by
(a) burning fuel after gas turbine
(b) injecting water in the compressor
(c) injecting ammonia into the combustion chamber
(d) all of the three above
(e) none of the above.
Ans:

187. The blades of gas turbine are made of
(a) mild steel
(b) stainless steel
(c) carbon steel
(d) high alloy seel
(e) high nicket alloy (neimonic).
Ans: e

188.  The following property is most important for material used for gas turbine blade
(a) toughness
(b) fatigue
(c) creep
(d) corrosion resistance
(e) bulk modulus.
Ans: c

189. The effective power of gas turbines is increased by adding the following in compressor
(a) ammonia and water vapour
(b) carbon dioxide
(c) nitrogen
(d) hydrogen
(e) none of the above.
Ans: a

190. High air-fuel ratio is used in gas turbines
(a) to increase the output
(b) to increase the efficiency
(c) to save fuel
(d) to reduce the exit temperature
(e) none of the above.
Ans: d

191. Air-fuel ratio in a jet engine will be of the order of
(a) 10: 1
(b) 15: 1
(c) 20 : 1
(d) 60 : 1
(e) 100 : 1
Ans: d

192. In which case the air-fuel ratio is likely to be maximum
(a) 2-stroke engine
(b) 4-stroke petrol engine
(c) 4-stroke diesef engine
(d) multi-cylinder engine
(e) gas turbine.
Ans: e

193. In jet engines the compression ratio
(a) varies as square root of the speed
(b) Varies linearly to the speed
(c) varies as square of the speed
(d) varies as cube of the speed
(e) is constant irrespective of variation in speed.
Ans: c

194. The specific output per kg mass flow rate of a gas turbine (having fixed efficiencies of compressor and turine and fixed higher and lower temperature) with increase in pressure ratio will
(a) increase first at fast rate and then slow
(b) increase first at slow rate and then fast
(c) decrease continuously
(d) first increase,  reach maximum and then decrease
(e) none of the above.
Ans: d

19 The working fluid in ai turbine is
(a) in two phases
(b) in three phases
(c) in a single phase
(d) in the form of air and water mixture
(e) gas and no air.
Ans: c

196. Gas turbine cycle with regenerator
(a) increases thermal efficiency
(b) allows high compression ratio
(c) decreases heat loss is exhaust
(d) allows operation at very high altitudes
(e) permits high moisture content fuel to be used.
Ans: a

197. The compression ratio in a gas turbine is of the roder of
(a) 3.5 : 1
(b) 5 : 1
(c) 8 : 1
(d) 12 : 1
(e) 20 : 1
Ans: c

198. Reheating in multistage expansion gas turbine results in
(a) high thermal efficiency
(b) reduction in compressor work
(c) decrease of heat loss in exhaust
(d) maximum work output
(e) none of the above.
Ans: d

199. The main purpose of reheating in gas turbine is to
(a) increase temperature
(b) reduce turbine size
(c) increase power output
(d) increase speed
(e) increase pressure ratio.
Ans: c

200. Reheating in gas turbine results in
(a) increase of work ratio
(b) decrease of thermal efficiency
(c) decrease of work ratio
(d) both (a) and (b) above
(e) both (b) and (c) above.
Ans: d

201. Work ratio of a gas turbine plant is ratio of
(a) net work output and work done by turbine
(b) net work output and heat supplied
(c) work done by turbine and heat supplied
(d) work done by turbine and net work output
(e) actual/heat drop and isentropic heat drop.
Ans: a

202. Work ratio of a gas turbine may be improved by f
(a) decreasing the compression work
(b) increasing the compression work
(c) increasing the turbine work
(d) decreasing the turbine work
(e) (a) and (c) above.
Ans: e

203. Maximum temprature in a gas turbine is of the order of COMPRESSORS, GAS TURBINES AND JET ENGINES
(a) 2500°C
(b) 2000°C
(c) 1500°C
(d) 1000°C
(e) 700°C.
Ans: e

21 In the aircraft propellers
(a) the propulsive matter is caused to flow around the propelled body
(b) propulsive matter is ejected from within the propelled body
(c) its functioning does not depend on presence of air
(d) all of the above
(e) none of the above.
Ans: d

216. In air breathing jet engine, the jet is formed by expading
(a) gases
(b) solids
(c) liquid
(d) plasma
(e) highly heated atmospheric air.
Ans: e

217. Ram-jet engine
(a) is self-operating at zero flight speed
(b) is not self-operating at zero^flight speed
(c) requires no air for its operation
(d) produces a jet consisting of plasma
(e) none of the above.
Ans: b

218. For speed above 3000 km/hour, it is more advantageous to use
(a) turbo-jet engine
(b) ram-jet engine
(c) propellers
(d) rockets
(e) hydraulic jet propulsion.
Ans: b

219. A simple turbo-jet engine is basically
(a) a propeller system
(b) gas-turbine engine equipped with a propulsive nozzle and
diffuser
(c) chemical rocket engine
(d) ram-jet engine
(e) none of the above.
Ans: b

220. Which of the following plants is smallest and lightest for genrating a given amount of power
(a) steam power plant
(b) petrol engine
(c) diesel engine'
(d) solar plant
(e) gas turbine plant.
Ans: e

221. In turbo fan engine, the jet velocity as compared to turbo-jet engine is
(a) less
(b) more
(c) same
(d) may be less or more depening upon speed
(e) none of the above.
Ans: a

222. Turbofan engine employs
(a) one air stream
(b) two or more air streams
(c) no air stream
(d) solid fuel firing
(e) rocket principle for its operation.
Ans: b

223. Pressure ratio in gas turbines is the ratio of
(a) compressor pressure ratio
(b) highest pressure to exhaust pressure
(c) inlet pressure to exhaust pressure
(d) pressures across the turbine
(e) none of the above.
Ans: b

224. Pick up the false statement
(a) gas turbine is a self-starting unit
(b) gas turbine does not require huge quantity of water like steam plant
(c) exhaust losses in gas turbine are high due to large mass flow rate
(d) overall efficiency of gas turbine plant is lower than that of a reciprocating engine
(e) gas turbine can be easily started and stopped and thus is best suited for peaking demands.
Ans: a

22 The efficiency and work ratio of a gas turbine plant can be increased by
(a) using mulit-stage compressor with mfercooler
(b) adding heat exchanger
(c) injecting water in/around combustion chamber
(d) reheating the air after partial expansion in the turbine
(e) all of the above.
Ans: e

226. Pick up the correct statement
(a) closed cycle gas turbine is an I.C engine
(b) gas turbine uses same working fluid over and over again
(c) air-fuel ratio in a gas turbine is 100 : 1
(d) ideal efficiency of closed cycle gas turbine plant is more than carnot cycle efficiency
(e) thrust in turbo-jet is produced by nozzle exit gases.
Ans: e

227. The  compression  ratio  in  a jet engine varies proportional to
(a) speed
(b) speed
(c) altitude
(d) Vspeed
(e) does not Vary.
Ans: b

228. The efficiency of jet engine is
(a) higher at ground
(b) higher at high altitudes
(c) same at all altitudes
(d) higher at high speed
(e) lower at low speed.
Ans: b

FLUID MECHANICS Mechanical Engineering

FINAL YEAR ENGINEERING PROJECTS...

• Automobile

• Aerospace

• Heat Transfer

• Fluid Flow

• Mechanical Engineering Basics

• Design and Analysis....     to name a few

final year engineering projects, final year projects, ieee projects , basics of mechanical engineering

​Tutoring

JJ TECHNICAL SOLUTIONS provides one-on-one coaching and mentoring to Mechanical Engineering project students to help them complete a state of the art Engineering Major/Minor project for B.Tech/M.Tech/Diploma courses, thereby assuring high marks and a good job.

final year engineering projects, final year projects, mechanical projects

​​​Our Instructors

All JJ TECHNICAL SOLUTIONS instructors are having wide and specialised knowledge in various branches of Engineering. We train our students to prepare them not only for graduation assessment but also in how to use your project to secure a job or higher study seat through a great interview presentation.

final year engineering projects, final year projects, mechanical projects ...STRIVING FOR EXCELLENCE...

final year engineering projects, final year projects, mechanical projects, basics of mechanical engineering, basic mechanical engineering 