76. 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
77. The resultant upward pressure of the fluid on an immersed body is called
(a) upthrust
(b) buoyancy
(c) centre of pressure
(d) all the above are correct
(e) none of above is correct.
Ans: b
78. The conditions for the stable equilibrium of a floating body are
(a) the meta-centre should lie above the centre of gravity
(b) the centre of buoyancy and the centre 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
79. Poise is the unit of
(a) surface tension
(b) capillarity
(c) viscosity
(d) shear stress in fluids
(e) buoyancy.
Ans: c
80. Metacentric height is given as the distance between
(a) the centre of gravity of the body andthe meta centre
(b) the centre of gravity of the body and the centre of buoyancy
(c) the centre of gravity of the body and the centre of pressure
(d) centre of buoyancy and metacentre
(e) none of the above.
Ans: a
81. 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
82. The centre of gravity of the volume of the liquid displaced by an immersed body is called
(a) meta-centre
(b) centre of pressure
(c) centre of buoyancy
(d) centre of gravity
(e) none of the above.
Ans: c
83. 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
84. 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
85. 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
86. 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
87. 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
88. 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
89. 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
90. 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
91. 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
92. 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
93. 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
94. The peoperty 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
95. 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
96. The units of dynamic or absolute viscosity are
(a) metres2 per sec
(b) kg sec/metre
(c) newton-sec per metre
(d) newton-sec2 per metre
(e) none of the above.
Ans: c
98. The continuity equation is connected with
(a) viscous/unviscous fluids
(b) compressibility of fluids
(c) conservation of mass
(d) steady/unsteady flow
(e) open channel/pipe flow.
Ans: c
99. The rise or depression of liquid in a tube due to surface tension wim 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
100. 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