A hemispherical tank of radius (R) has an orifice of cross-sectional area (a) at its bottom and is full of liquid. The time required to empty the tank completely is
14π R1/2/15Cd × a √(2g)
14π R3/2/15Cd × a √(2g)
14π R5/2/15Cd × a √(2g)
14π R7/2/15Cd × a √(2g)
Correct Answer :
C. 14π R5/2/15Cd × a √(2g)
Related Questions
The siphon will work satisfactorily, if the minimum pressure in the pipe is __________ vapour pressure of liquid.
Equal to
Less than
More than
None of these
The pressure of fluid due to hammer blow is
Directly proportional to density of fluid
Inversely proportional to density of fluid
Directly proportional to (density)1/2 of fluid
Inversely proportional to (density)1/2 of fluid
When the pressure intensity at a point is more than the local atmospheric pressure, then the difference of these two pressures is called
Gauge pressure
Absolute pressure
Positive gauge pressure
Vacuum pressure
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 acts at a distance __________ from the liquid surface.
H/3
H/2
2H/3
3H/4
The diameter of the nozzle (d) for maximum transmission of power is given by (where D = Diameter of pipe, f = Darcys coefficient of friction for pipe, and l = Length of pipe)
d = (D⁵/8fl)1/2
d = (D⁵/8fl)1/3
d = (D⁵/8fl)1/4
d = (D⁵/8fl)1/5
In an immersed body, centre of pressure is
At the centre of gravity
Above the centre of gravity
Below be centre of gravity
Could be above or below e.g. depending on density of body and liquid
A point, in a compressible flow where the velocity of fluid is zero, is called
Critical point
Vena contracta
Stagnation point
None of these
A manometer is used to measure
Low pressure
Moderate pressure
High pressure
Atmospheric pressure
The intensity of pressure on an immersed surface __________ with the increase in depth.
Does not change
Increases
Decreases
None of these
Coefficient of discharge Cd is equal to (where Cc = Coefficient of contraction, Cv = Coefficient of velocity, and Cr = Coefficient of resistance)
Cc × Cv
Cc × Cr
Cv × Cr
Cc/Cr
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
The power transmitted through the nozzle is maximum when the head lost due to friction in the pipe is __________ of the total supply head.
One-half
One-third
Two-third
None of these
In an internal mouthpiece, if the jet after contraction does not touch the sides of the mouthpiece, then the mouthpiece is said to be
Running full
Running free
Partially running full
Partially running free
A body floats in stable equilibrium
When its meatcentric height is zero
When the metacentre is above C.G.
When its e.g. is below its center of buoyancy
Metacentre has nothing to do with position of e.g. for determining stability
The total energy of each particle at various places in the case of perfect incompressible fluid flowing in continuous stream
Keeps on increasing
Keeps on decreasing
Remain constant
May increase/decrease
In case of flow through parallel pipes,
The head loss for all the pipes is same
The total discharge is equal to the sum of discharges in the various pipes
The total head loss is the sum of head losses in the various pipes
Both (A) and (B)
When the water level on the downstream side of a weir is above the top surface of a weir, the weir is known as
Narrow-crested weir
Broad-crested weir
Ogee weir
Submerged weir
Ratio of inertia force to elastic force is known as
Mach number
Froude number
Reynolds number
Weber's number
True one-dimensional 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 plane
According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to
The weight of the body
More than the weight of the body
Less than the weight of the body
Weight of the fluid displaced by the body
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
A piece of metal of specific gravity 7 floats in mercury of specific gravity 13.6. What fraction of its volume is under mercury?
0.5
0.4
0.515
0.5
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Kinematic viscosity in C. G. S. units
Kinematic viscosity in M. K. S. units
Dynamic viscosity in M. K. S. units
Dynamic viscosity in S. I. units
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Actual velocity of jet at vena contracta to the theoretical velocity
Area of jet at vena contracta to the area of orifice
Actual discharge through an orifice to the theoretical discharge
None of the above
The divergent portion of a Venturimeter is made longer than convergent portion in order to
Avoid the tendency of breaking away the stream of liquid
To minimise frictional losses
Both (A) and (B)
None of these
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Absolute temperature
Temperature
Density
Modulus of elasticity
Whenever a plate is held immersed at some angle with the direction of flow of the liquid, it is subjected to some pressure. The component of this pressure, in the direction of flow of the liquid, is known as
Lift
Drag
Stagnation pressure
Bulk modulus
Practical fluids
Are viscous
Possess surface tension
Are compressible
Possess all the above properties
The point at which the resultant pressure on an immersed surface acts, is known as
Centre of gravity
Centre of depth
Centre of pressure
Centre of immersed surface
The ratio of the inertia force to the elastic force is called
Reynold's number
Froude's number
Weber's number
Mach number