A submerged body is said to be in a stable equilibrium, if its centre of gravity __________ the centre of buoyancy.
Coincides with
Lies below
Lies above
None of these
Correct Answer :
B. Lies below
Related Questions
The region between the separation streamline and the boundary surface of the solid body is known as
Wake
Drag
Lift
Boundary layer
Free surface of a liquid tends to contract to the smallest possible area due to force of
Surface tension
Viscosity
Friction
Cohesion
A weir, generally, used as a spillway of a dam is
Narrow crested weir
Broad crested weir
Ogee weir
Submerged weir
Falling drops of water become spheres due to the property of
Surface tension of water
Compressibility of water
Capillarity of water
Viscosity of water
The hammer blow in pipes occurs when
There is excessive leakage in the pipe
The pipe bursts under high pressure of fluid
The flow of fluid through the pipe is suddenly brought to rest by closing of the valve
The flow of fluid through the pipe is gradually brought to rest by closing of the valve
Pressure of the order of 10 torr can be measured by
Bourdon tube
Pirani Gauge
Micro-manometer
Lonisation gauge
A flow in which the volume of a fluid and its density does not change during the flow is called _________ flow.
Incompressible
Compressible
Viscous
None of these
The most economical section of a trapezoidal channel is one which has hydraulic mean depth equal to
1/2 × depth
1/2 × breadth
1/2 × sloping side
1/4 × (depth + breadth)
The stress-strain relation of the Newtonian fluid is
Linear
Parabolic
Hyperbolic
Inverse type
The Euler's equation for the motion of liquids is based upon the assumption that
The fluid is non - viscous, homogeneous and incompressible
The velocity of flow is uniform over the section
The flow is continuous, steady and along the stream line
All of the above
The pressure at a point in a fluid will not be same in all the directions when the fluid is
Moving
Viscous
Viscous and static
Viscous and moving
The power transmitted through the pipe is maximum when the head lost due to friction is equal to
One-fourth of the total supply head
One-third of the total supply head
One-half of the total supply head
Two-third of the total supply head
Which of the following instrument can be used for measuring speed of an aeroplane?
Venturimeter
Orifice plate
Pitot tube
Rotameter
The vapour pressure over the concave surface is
Less man the vapour pressure over the plane surface
Equal to the vapour pressure over the plane surface
Greater than the vapour pressure over the plane surface
Zero
The capillary rise at 20°C in a clean glass tube of 1 mm bore containing water is approximately
5 mm
10 mm
20 mm
30 mm
According to equation of continuity,
w1a1 = w2a2
w1v1 = w2v2
a1v1 = a2v2
a1/v1 = a2/v2
Cavitation will begin when
The pressure at any location reaches an absolute pressure equal to the saturated vapour pressure of the liquid
Pressure becomes more than critical pressure
Flow is increased
Pressure is increased
Rotameter is a device used to measure
Absolute pressure
Velocity of fluid
Flow
Rotation
Resultant pressure of the liquid in the case of an immersed body acts through
Centre of gravity
Centre of pressure
Metacentre
Centre of buoyancy
A flow in which the viscosity of fluid is dominating over the inertia force is called
Steady flow
Unsteady flow
Laminar flow
Turbulent flow
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
Higher than the surface of liquid
The same as the surface of liquid
Lower than the surface of liquid
Unpredictable
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
2 meters of water column
3 meters of water column
5 meters of water column
6 meters of water Column
Newton's law of viscosity is a relationship between
Shear stress and the rate of angular distortion
Shear stress and viscosity
Shear stress, velocity and viscosity
Pressure, velocity and viscosity
A flow through a long pipe at constant rate is called
Steady uniform flow
Steady non-uniform flow
Unsteady uniform flow
Unsteady non-uniform flow
The force of buoyancy is always __________ the weight of the liquid displaced by the body.
Equal to
Less than
More than
None of these
Coefficient of resistance is the ratio of
Actual velocity of jet at vena-contracta to the theoretical velocity
Area of jet at vena-contracta to the area of orifice
Loss of head in the orifice to the head of water available at the exit of the orifice
Actual discharge through an orifice to the theoretical discharge
Manometer is used to measure
Pressure in pipes, channels etc.
Atmospheric pressure
Very low pressure
Difference of pressure between two points
The pressure of liquid at throat in a Venturimeter is __________ than that at inlet.
Higher
Lower
Same
None of these
A jet of water discharging from a 40 mm diameter orifice has a diameter of 32 mm at its vena contracta. The coefficient of contraction is
0.46
0.64
0.78
0.87
To avoid vaporisation in the pipe line, the pipe line over the ridge is laid such that it is not more than
2.4 m above the hydraulic gradient
6.4 m above the hydraulic gradient
10.0 m above the hydraulic gradient
5.0 above the hydraulic gradient