Choose the wrong statement
Any weight, floating or immersed in a liquid, is acted upon by a buoyant force
Buoyant force is equal to the weight of the liquid displaced
The point through which buoyant force acts, is called the center of buoyancy
Center of buoyancy is located above the center of gravity of the displaced liquid
Correct Answer :
D. Center of buoyancy is located above the center of gravity of the displaced liquid
Related Questions
In a footstep bearing, if the radius of the shaft is doubled, then the torque required to overcome the viscous resistance will be
Double
Four times
Eight times
Sixteen times
Uniform flow occurs when
The direction and magnitude of the velocity at all points are identical
The velocity of successive fluid particles, at any point, is the same at successive periods of time
The magnitude and direction of the velocity do not change from point to point in the fluid
The fluid particles move in plane or parallel planes and the streamline patterns are identical in each pleasure
The torque required to overcome viscous resistance of a footstep bearing is (where μ = Viscosity of the oil, N = Speed of the shaft, R = Radius of the shaft, and t = Thickness of the oil film)
μπ²NR/60t
μπ²NR²/60t
μπ²NR³/60t
μπ²NR⁴/60t
The stability of a dam is checked for
Tension at the base
Overturning of the wall or dam
Sliding of the wall or dam
All of these
If a body floating in a liquid occupies a new position and remains at rest in this new position, when given a small angular displacement, the body is said to be in __________ equilibrium.
Neutral
Stable
Unstable
None of these
The centre of pressure acts __________ the centre of gravity of immersed surface.
At
Above
Below
None of these
The total head of a liquid particle in motion is equal to
Pressure head + kinetic head + potential head
Pressure head - (kinetic head + potential head)
Potential head - (pressure head + kinetic head)
Kinetic head - (pressure head + potential head)
A glass tube of small diameter (d) is dipped in fluid. The height of rise or fall in the tube given by (where w = Specific weight of liquid, α = Angle of contact of the liquid surface, and σ = Surface tension)
4wd/σ cosα
σ cosα/4wd
4σ cosα/wd
wd/4σ cosα
A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if
Length of both the pipes is same
Diameter of both the pipes is same
Loss of head and discharge of both the pipes is same
Loss of head and velocity of flow in both the pipes is same
The variation in the volume of a liquid with the variation of pressure is called its
Surface tension
Compressibility
Capillarity
Viscosity
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 dynamic viscosity of the liquid __________ with rise in temperature.
Remain unaffected
Increases
Decreases
None of these
The meatcentric height is the distance between the
Centre of gravity of the floating body and the centre of buoyancy
Centre of gravity of the floating body and the metacentre
Metacentre and centre of buoyancy
Original centre of buoyancy and new centre of buoyancy
The length of the divergent cone in a Venturimeter is __________ that of the convergent cone.
Equal to
Double
Three to four times
Five to six times
According to Bernoulli's equation
Z + p/w + v²/2g = constant
Z + p/w - v²/2g = constant
Z - p/w + v²/2g = constant
Z - p/w - v²/2g = constant
The loss of head at entrance in a pipe is (where v = Velocity of liquid in the pipe)
v²/2g
0.5v²/2g
0.375v²/2g
0.75v²/2g
The atmospheric pressure at sea level is
103 kN/m2
10.3 m of water
760 mm of mercury
All of these
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 vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. The total pressure on the wall per unit length is (where w = Specific weight of liquid, and H = Height of liquid)
wH
wH/2
wH2/2
wH2/3
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
h
wh
w/h
h/w
The error in discharge (dQ/Q) to the error in measurement of head (dH/H) over a rectangular notch is given by
dQ/Q = (1/2) × (dH/H)
dQ/Q = (3/4) × (dH/H)
dQ/Q = (dH/H)
dQ/Q = (3/2) × (dH/H)
The tendency of a liquid surface to contract is due to the following property
Cohesion
Adhesion
Viscosity
Surface tension
The torque required to overcome viscous resistance of a collar bearing is (where R1 andR2 = External and internal radius of collar)
(μπ²N/60t) × (R₁ - R₂)
(μπ²N/60t) × (R₁² - R₂²)
(μπ²N/60t) × (R₁³ - R₂³)
(μπ²N/60t) × (R₁⁴ - R₂⁴)
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
0.83
0.6
0.4
0.3
Reynold's number is the ratio of the inertia force to the
Surface tension force
Viscous force
Gravity force
Elastic force
The coefficient of discharge for an external mouthpiece depends upon
Velocity of liquid
Pressure of liquid
Area of mouthpiece
Length of mouthpiece
The discharge through a siphon spillway is
Cd × a × √(2gH)
Cd × a × √(2g) × H3/2
Cd × a × √(2g) × H2
Cd × a × √(2g) × H5/2
Working principle of dead weight pressure gauge tester is based on
Pascal's law
Dalton's law of partial pressure
Newton's law of viscosity
Avogadro's hypothesis
A flow is called super-sonic if the
Velocity of flow is very high
Discharge is difficult to measure
Mach number is between 1 and 6
None of these
The loss of head due to viscosity for laminar flow in pipes is (where d = Diameter of pipe, l = Length of pipe, v = Velocity of the liquid in the pipe, μ = Viscosity of the liquid, and w = Specific weight of the flowing liquid)
4μvl/wd²
8μvl/wd²
16μvl/wd²
32μvl/wd²