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All questions of Fluid Mechanics for Civil Engineering (CE) Exam
A longitudinal rectangular surface is hanged into the water such that its top and bottom points are at depth of 1.5 m and 6.0 m respectively. The depth of center of pressure (m) from the top surface is _____.- a)3.8
- b)4.2
- c)4.6
- d)4.8
Correct answer is option 'B'. Can you explain this answer?
A longitudinal rectangular surface is hanged into the water such that its top and bottom points are at depth of 1.5 m and 6.0 m respectively. The depth of center of pressure (m) from the top surface is _____.
a)
3.8
b)
4.2
c)
4.6
d)
4.8
|
Nilanjan Chawla answered |
θ = 90°
A = 1 × 4.5 m2
h¯CP= 4.2 metre
A hydraulic jump occurs when the grade changes from:- a)mild to milder
- b)mild to steep
- c)steep to steeper
- d)steep to mild
Correct answer is option 'D'. Can you explain this answer?
A hydraulic jump occurs when the grade changes from:
a)
mild to milder
b)
mild to steep
c)
steep to steeper
d)
steep to mild
|
|
Nilanjan Chawla answered |
When the flow conditions changes form super critical (Fr > 1) to subcritical (Fr < 1), this results to an abrupt rise of water accompanied by turbulent rollers is called as hydraulic Jump or standing wave.
The hydraulic Jump occurs when the grade changes from sleep to mild
If a thin plate is held parallel to fluid stream the pressure drag on it is:- a)Maximum
- b)Minimum
- c)Zero
- d)None of these
Correct answer is option 'C'. Can you explain this answer?
If a thin plate is held parallel to fluid stream the pressure drag on it is:
a)
Maximum
b)
Minimum
c)
Zero
d)
None of these
|
|
Mehul Choudhury answered |
Viscous forces and pressure forces are responsible for drag forces. There are two types of drag forces present pressure drag and skin friction drag. Pressure drag is due to the wake region behind the body and skin friction drag is due to the viscosity of the fluid.
In case of flow over a thin plate placed parallel to a stream of flowing fluid, the flow separation (if occurs), would occur only towards the rear end and the wake is negligibly small. The resulting pressure drag will also be very small, approximate to zero.
On the other hand, pressure drag will be large when the thin plate is held perpendicular to the flow.
The most economical section of circular channel for maximum discharge is obtained when (Where, d is the diameter of circular section)- a)depth of water = 0.95 d
- b)wetter perimeter = 2.6 d
- c)hydraulic mean depth = 0.29 d
- d)Any one of these
Correct answer is option 'D'. Can you explain this answer?
The most economical section of circular channel for maximum discharge is obtained when (Where, d is the diameter of circular section)
a)
depth of water = 0.95 d
b)
wetter perimeter = 2.6 d
c)
hydraulic mean depth = 0.29 d
d)
Any one of these
|
|
Sahil Chawla answered |
D = depth of flow
d = diameter of pipe
Rm = Hydraulic Mean depth = A/P
Perimeter, P = αd
Condition for Maximum Discharge for Circular Section:
α = 154° = 2.65 radians
D = 0.95 d
Rm = 0.29 d
Condition for Maximum Velocity for Circular Section:
α = 128.75° = 2.25 radians
D = 0.81 d
Rm = 0.3 d
The velocity potential which follow the equation of continuity is ________- a)x2y
- b)x2- y2
- c)cos x
- d)x2 + y2
Correct answer is option 'B'. Can you explain this answer?
The velocity potential which follow the equation of continuity is ________
a)
x2y
b)
x2- y2
c)
cos x
d)
x2 + y2
|
|
Sahil Mehra answered |
Velocity Potential function (ϕ) is given as = x2 - y2
u = - 2x
V = 2y
For continuity to be satisfied
-2 + 2 = 0
(Hence satisfied)
Specific gravity of water is 1.0 which is reported at a temperature of:- a)100°C
- b)104°C
- c)4°C
- d)10°C
Correct answer is option 'C'. Can you explain this answer?
Specific gravity of water is 1.0 which is reported at a temperature of:
a)
100°C
b)
104°C
c)
4°C
d)
10°C
|
Nidhi Patel answered |
Specific gravity of water is 1.0 which is reported at a temperature of 4°C. Specific gravity is a measure of density of liquid.
Some interesting facts about Specific gravity:
Specific gravity of water is actually a density of water in gram per cubic centimetre.
The eddy viscosity for turbulent flow is- a)a function of temperature only
- b)a physical property of the fluid
- c)dependent on flow
- d)independent of the flow
Correct answer is option 'C'. Can you explain this answer?
The eddy viscosity for turbulent flow is
a)
a function of temperature only
b)
a physical property of the fluid
c)
dependent on flow
d)
independent of the flow
|
|
Gauri Sarkar answered |
1. Flows become turbulent due to differences in velocity inside them, and the flow resistance increases. This resistive force acting on flows due to turbulence is called the Reynolds stress. This is an imaginary force that appears when flow fields are seen with coarse graining by time-averaging.
2. Viscosity, the proportionality constant of viscous force, is a physical quantity dependent on the type of material, while eddy viscosity is a physical quantity dependent on the state of flow.
A streamlined body is defined as a body about which ________.- a)The flow is laminar
- b)The flow is along the stream lines
- c)The flow separation is suppressed
- d)The drag is zero
Correct answer is option 'C'. Can you explain this answer?
A streamlined body is defined as a body about which ________.
a)
The flow is laminar
b)
The flow is along the stream lines
c)
The flow separation is suppressed
d)
The drag is zero
|
|
Meghana Desai answered |
A stream lined body is defined as the body whose surface coincides with the stream - lines, when the body is placed in a flow. In that case the separation of flow will take place only at trailing edge (or rearmost part of the body).
Behind a stream lined body, wake formation zone will be very small and consequently the pressure drag will be very small. Thus the total drag on the stream lined body will be due to friction (shear) only.
The correct statement about ideal fluid is:- a)An ideal fluid is incompressible, non-viscous and has infinite bulk modulus.
- b)An ideal fluid is incompressible, non-viscous and has finite bulk modulus.
- c)An ideal fluid is compressible, viscous and has infinite bulk modulus.
- d)An ideal fluid is compressible, non-viscous and has infinite bulk modulus.
Correct answer is option 'A'. Can you explain this answer?
The correct statement about ideal fluid is:
a)
An ideal fluid is incompressible, non-viscous and has infinite bulk modulus.
b)
An ideal fluid is incompressible, non-viscous and has finite bulk modulus.
c)
An ideal fluid is compressible, viscous and has infinite bulk modulus.
d)
An ideal fluid is compressible, non-viscous and has infinite bulk modulus.
|
Om Pillai answered |
The correct statement about ideal fluid is:
An ideal fluid is incompressible, non-viscous, and has an infinite bulk modulus.
Explanation:
An ideal fluid is a theoretical concept used in fluid mechanics to simplify the analysis of fluid flow. It is defined by certain characteristics that differentiate it from real fluids.
Incompressibility:
- An ideal fluid is considered to be incompressible, which means its density remains constant regardless of the pressure applied.
- In practical terms, this implies that the volume of an ideal fluid does not change even when subjected to high pressures.
- This assumption is often valid for liquids like water or oil, but not for gases.
Non-viscous nature:
- An ideal fluid is assumed to be non-viscous, meaning it has zero viscosity.
- Viscosity is the property of a fluid that causes it to resist flow and create internal friction.
- In an ideal fluid, there is no internal friction between fluid layers, and the fluid flows without any resistance.
Infinite bulk modulus:
- The bulk modulus is a property that measures the compressibility or resistance to compression of a fluid.
- An ideal fluid is considered to have an infinite bulk modulus, which means it is completely resistant to compression.
- In practical terms, this implies that an ideal fluid cannot be compressed or its volume cannot be changed by applying external pressure.
- This assumption is valid for incompressible fluids like liquids, where the change in volume due to pressure is negligible.
Conclusion:
The correct statement about an ideal fluid is that it is incompressible, non-viscous, and has an infinite bulk modulus. These assumptions help simplify fluid flow analysis and are applicable to certain fluids like liquids. However, it is important to note that real fluids do not completely fulfill these ideal characteristics.
An ideal fluid is incompressible, non-viscous, and has an infinite bulk modulus.
Explanation:
An ideal fluid is a theoretical concept used in fluid mechanics to simplify the analysis of fluid flow. It is defined by certain characteristics that differentiate it from real fluids.
Incompressibility:
- An ideal fluid is considered to be incompressible, which means its density remains constant regardless of the pressure applied.
- In practical terms, this implies that the volume of an ideal fluid does not change even when subjected to high pressures.
- This assumption is often valid for liquids like water or oil, but not for gases.
Non-viscous nature:
- An ideal fluid is assumed to be non-viscous, meaning it has zero viscosity.
- Viscosity is the property of a fluid that causes it to resist flow and create internal friction.
- In an ideal fluid, there is no internal friction between fluid layers, and the fluid flows without any resistance.
Infinite bulk modulus:
- The bulk modulus is a property that measures the compressibility or resistance to compression of a fluid.
- An ideal fluid is considered to have an infinite bulk modulus, which means it is completely resistant to compression.
- In practical terms, this implies that an ideal fluid cannot be compressed or its volume cannot be changed by applying external pressure.
- This assumption is valid for incompressible fluids like liquids, where the change in volume due to pressure is negligible.
Conclusion:
The correct statement about an ideal fluid is that it is incompressible, non-viscous, and has an infinite bulk modulus. These assumptions help simplify fluid flow analysis and are applicable to certain fluids like liquids. However, it is important to note that real fluids do not completely fulfill these ideal characteristics.
An isentropic process is always...- a)reversible and isothermal
- b)irreversible and adiabatic
- c)frictionless and adiabatic
- d)frictionless and isothermal
Correct answer is option 'C'. Can you explain this answer?
An isentropic process is always...
a)
reversible and isothermal
b)
irreversible and adiabatic
c)
frictionless and adiabatic
d)
frictionless and isothermal
|
|
Nikhil Majumdar answered |
In thermodynamics an isentropic process is an idealized thermodynamic process. that is both adiabatic and reversible. The work transfer of system is friction-less and there is no transfer of heat as matter.
For Bernoulli’s equation to remain valid, which of the following is NOT required?- a)Incompressible medium
- b)Steady flow
- c)Irrotational flow
- d)Ideal gas fluid
Correct answer is option 'D'. Can you explain this answer?
For Bernoulli’s equation to remain valid, which of the following is NOT required?
a)
Incompressible medium
b)
Steady flow
c)
Irrotational flow
d)
Ideal gas fluid
|
Bijoy Kapoor answered |
The law states that P X V = n X (R) X T, where P is pressure, V is volume, n is the number of moles of molecules, T is the absolute temperature, and R is the gas constant (8.314 joules per degree Kelvin or 1.985 calories per degree Celsius).
For a uniform flow with depth of 0.6 m and Froude number of 2.0 in a rectangular channel, the specific energy will be -- a)0.8 m
- b)2.6 m
- c)4.8 m
- d)1.8 m
Correct answer is option 'D'. Can you explain this answer?
For a uniform flow with depth of 0.6 m and Froude number of 2.0 in a rectangular channel, the specific energy will be -
a)
0.8 m
b)
2.6 m
c)
4.8 m
d)
1.8 m
|
|
Aashna Chakraborty answered |
Given data:
Depth of flow (y) = 0.6 m
Froude number (Fr) = 2.0
To find: Specific energy (E)
Formula used:
Specific energy (E) = y + V^2 / 2g
Where,
V = velocity of flow
g = acceleration due to gravity
Calculation:
We know that, Froude number (Fr) = V / √(gy)
Fr = 2.0
y = 0.6 m
∴ V = Fr √(gy)
V = 2.0 √(9.81 × 0.6)
V = 3.86 m/s
Now, putting the values of y and V in the formula of specific energy,
E = y + V^2 / 2g
E = 0.6 + (3.86)^2 / (2 × 9.81)
E = 1.8 m
Therefore, the specific energy of the given uniform flow with depth of 0.6 m and Froude number of 2.0 in a rectangular channel is 1.8 m. Hence, option (d) is the correct answer.
Depth of flow (y) = 0.6 m
Froude number (Fr) = 2.0
To find: Specific energy (E)
Formula used:
Specific energy (E) = y + V^2 / 2g
Where,
V = velocity of flow
g = acceleration due to gravity
Calculation:
We know that, Froude number (Fr) = V / √(gy)
Fr = 2.0
y = 0.6 m
∴ V = Fr √(gy)
V = 2.0 √(9.81 × 0.6)
V = 3.86 m/s
Now, putting the values of y and V in the formula of specific energy,
E = y + V^2 / 2g
E = 0.6 + (3.86)^2 / (2 × 9.81)
E = 1.8 m
Therefore, the specific energy of the given uniform flow with depth of 0.6 m and Froude number of 2.0 in a rectangular channel is 1.8 m. Hence, option (d) is the correct answer.
The specific speed of a pump is defined as the speed of a unit of such a size that it discharge:- a)unit discharge at unit power
- b)unit work at unit head loss
- c)unit discharge at unit head
- d)unit volume at unit time
Correct answer is option 'C'. Can you explain this answer?
The specific speed of a pump is defined as the speed of a unit of such a size that it discharge:
a)
unit discharge at unit power
b)
unit work at unit head loss
c)
unit discharge at unit head
d)
unit volume at unit time
|
|
Anisha Chakraborty answered |
The specific speed of a pump is defined as speed at which pump generates unit discharge under unit head.
where Q=discharge, H=head, Ns= specific speed, N= speed of pump.Quick sand comes under:- a)Dilatant fluid
- b)Pseudoplastic fluid
- c)Thixotropic fluid
- d)Rheopectic fluid
Correct answer is option 'A'. Can you explain this answer?
Quick sand comes under:
a)
Dilatant fluid
b)
Pseudoplastic fluid
c)
Thixotropic fluid
d)
Rheopectic fluid
|
|
Pallabi Chavan answered |
Newtonian Fluids: Air, water, mercury, glycerine, kerosene and other engineering fluids under normal circumstances.
Pseudoplastic: Fine particle suspension, gelatine, blood, milk, paper pulp, polymeric solutions such as rubbers, paints.
Dilatant fluids: Ultra fine irregular particle suspension, sugar in water, aqueous suspension of rice starch, quicksand, butter printing ink.
Ideal plastics or Bingham fluids: Sewage sludge, drilling muds.
Viscoelastic fluids: Liquids solid combination in pipe flow, bitumen, tar, asphalt, polymerized fluids with drag reduction features.
Thixotropic: Printer’s ink, crude oil, lipstick, certain paints and enamels.
Rheopectic fluids: Very rare liquid - solid suspensions, gypsum suspension in water and bentonite solutions.
In a lock gate, the reaction between two gates is- a)
- b)
- c)
- d)
Correct answer is option 'C'. Can you explain this answer?
In a lock gate, the reaction between two gates is
a)
b)
c)
d)
|
|
Nidhi Patel answered |
The lock gates are provided in navigation chambers to change a water level in a canal or river in navigation. There are two sets of gates, one set on either side of the chamber.
In a lock gate, the reaction between the two gates (R) is given by:
P = Resultant water pressure on the lock gate
α = Inclination of the gate with the normal to the side of the lock.
Two pumps can operate independently at heads H1, H2 and discharges Q1, Q2, respectively. If the pumps are connected in parallel, then what are the resulting discharge (Q) and head (H)?- a)Q = Q1 + Q2; H = H1 + H2
- b)Q = Q1 - Q2; H = H1 + H2
- c)Q = Q1 = Q2; H = H1 = H2
- d)Q = Q1 + Q2; H = H1 = H2
Correct answer is option 'D'. Can you explain this answer?
Two pumps can operate independently at heads H1, H2 and discharges Q1, Q2, respectively. If the pumps are connected in parallel, then what are the resulting discharge (Q) and head (H)?
a)
Q = Q1 + Q2; H = H1 + H2
b)
Q = Q1 - Q2; H = H1 + H2
c)
Q = Q1 = Q2; H = H1 = H2
d)
Q = Q1 + Q2; H = H1 = H2
|
|
Akash Mukherjee answered |
Pumps in Parallel:
Same Head: H = H1 = H2
Add the discharge: Q = Q1 + Q2
Pumps in Series:
Same Discharge: Q = Q1 = Q2
Add the heads: H = H1 + H2
The point at which the resultant pressure on a immersed surface acts, is known as:- a)Centre of Gravity
- b)Centre of depth
- c)Centre of pressure
- d)Centre of immersed surface
Correct answer is option 'C'. Can you explain this answer?
The point at which the resultant pressure on a immersed surface acts, is known as:
a)
Centre of Gravity
b)
Centre of depth
c)
Centre of pressure
d)
Centre of immersed surface
|
|
Pallabi Tiwari answered |
Centre of pressure:
The point of action of total hydrostatic force on a submerged surface is called the centre of pressure. It is the point at which the resultant pressure on a immersed surface acts.
The hydraulic grade line for flow in a pipe of constant internal diameter ______.- a)coincides with the physical centreline of the pipe
- b)is always above the centreline of the pipe
- c)is always sloping down in the direction of flow
- d)is always above the total energy grade line
Correct answer is option 'C'. Can you explain this answer?
The hydraulic grade line for flow in a pipe of constant internal diameter ______.
a)
coincides with the physical centreline of the pipe
b)
is always above the centreline of the pipe
c)
is always sloping down in the direction of flow
d)
is always above the total energy grade line
|
|
Manasa Bose answered |
For the pipe of constant diameter, the hydraulic gradient line is always sloping down in the direction of flow and is parallel to total energy line and the difference between both the lines represents velocity head. Due to hf(head loss due to friction) along the length of pipe, H.G.L always sloping down.
The term alternate depths in open channel flow is used to designate the depths- a)At the beginning and end of a hydraulic jump
- b)Having the same kinetic energy for a given discharge
- c)Having the same specific energy for a given discharge
- d)At the beginning and end of a gradually varied flow profile
Correct answer is option 'C'. Can you explain this answer?
The term alternate depths in open channel flow is used to designate the depths
a)
At the beginning and end of a hydraulic jump
b)
Having the same kinetic energy for a given discharge
c)
Having the same specific energy for a given discharge
d)
At the beginning and end of a gradually varied flow profile
|
|
Aarav Kulkarni answered |
For a given discharge Q in a channel, there will be two depths for a given specific energy. These two depths are known as alternate depths.
For a vacuum pressure of 4.5 m of water, the equivalent absolute pressure is:- a)5.83 m of water
- b)14.83 m of water
- c)12.33 m of water
- d)8.83 m of water
Correct answer is option 'A'. Can you explain this answer?
For a vacuum pressure of 4.5 m of water, the equivalent absolute pressure is:
a)
5.83 m of water
b)
14.83 m of water
c)
12.33 m of water
d)
8.83 m of water
|
|
Anisha Chakraborty answered |
Absolute pressure = gauge pressure + local atmospheric pressure
-ve gauge pressure = vacuum pressure = 4.5 m of water
Local atmospheric pressure of water = 10.3 m of water
Equivalent absolute pressure = -4.5 + 10.33 = 5.83 m of water
The flow of water in a wash hand basin when it is being emptied through a central opening, is an example of- a)Free vortex
- b)Forced vortex
- c)Rotational vortex
- d)Rankine vortex
Correct answer is option 'A'. Can you explain this answer?
The flow of water in a wash hand basin when it is being emptied through a central opening, is an example of
a)
Free vortex
b)
Forced vortex
c)
Rotational vortex
d)
Rankine vortex
|
|
Pallabi Tiwari answered |
In a free vortex flow total mechanical energy remains constant. There is neither any energy interaction between an outside source and the flow, nor is there any dissipation of mechanical energy within the flow. The fluid rotates by virtue of some rotation previously imparted to it or because of some internal action.
Some examples are a whirlpool in a river, the rotatory flow that often arises in a shallow vessel when liquid flows out through a hole in the bottom (when water flows out from a bathtub or a wash basin), and flow in a centrifugal pump case just outside the impeller.
Separation of flow occurs when pressure gradient- a)tends to approach zero
- b)becomes negative
- c)reduces to a value when vapor formation starts
- d)None of these
Correct answer is option 'D'. Can you explain this answer?
Separation of flow occurs when pressure gradient
a)
tends to approach zero
b)
becomes negative
c)
reduces to a value when vapor formation starts
d)
None of these
|
|
Sahil Mehra answered |
Flow separation occurs when the pressure gradient is positive and velocity gradient is negative.
In a laminar flow in a pipe the shear stress is:- a)Maximum at center.
- b)Maximum at boundary and decreasing linearly to zero.
- c)Maximum at wall and decreasing longitudinally towards centre.
- d)Maximum at definite distance from the wall.
Correct answer is option 'B'. Can you explain this answer?
In a laminar flow in a pipe the shear stress is:
a)
Maximum at center.
b)
Maximum at boundary and decreasing linearly to zero.
c)
Maximum at wall and decreasing longitudinally towards centre.
d)
Maximum at definite distance from the wall.
|
|
Anmol Roy answered |
Shear stress distribution in laminar flow in a pipe
In a laminar flow in a pipe, the shear stress distribution refers to how the shear stress varies across the cross-section of the pipe. The shear stress is the force per unit area that acts parallel to the flow direction and it is caused by the viscosity of the fluid.
Understanding laminar flow
Laminar flow is a type of flow where the fluid particles move in parallel layers, with little mixing between the layers. It occurs at low flow velocities and is characterized by smooth and orderly flow patterns. In a pipe, the velocity of the fluid is highest at the center of the pipe and decreases towards the walls.
Shear stress distribution in laminar flow
The shear stress distribution in laminar flow can be determined by applying the principle of fluid mechanics. The shear stress at a given point is proportional to the velocity gradient perpendicular to the flow direction.
Maximum shear stress at the boundary
In laminar flow in a pipe, the maximum shear stress occurs at the boundary or wall of the pipe. This is because the fluid in contact with the wall has zero velocity due to the no-slip condition, which states that the fluid at the wall must have the same velocity as the wall. Therefore, the velocity gradient is highest at the wall, resulting in the highest shear stress.
Decreasing shear stress towards the center
As we move away from the wall towards the center of the pipe, the velocity of the fluid gradually increases. This leads to a decrease in the velocity gradient and consequently a decrease in the shear stress. The shear stress distribution follows a linear profile, with the maximum value at the wall and decreasing linearly to zero at the center of the pipe.
Explanation of the correct answer (Option B)
Option B states that the maximum shear stress occurs at the boundary and decreases linearly to zero. This is the correct answer because it accurately describes the shear stress distribution in laminar flow in a pipe. The shear stress is highest at the wall due to the no-slip condition and decreases towards the center of the pipe as the velocity gradient decreases.
Conclusion
In summary, in laminar flow in a pipe, the shear stress is maximum at the boundary or wall of the pipe and decreases linearly to zero towards the center of the pipe. This shear stress distribution is a result of the velocity gradient perpendicular to the flow direction. Understanding the shear stress distribution is important in analyzing fluid flow and designing pipe systems in various engineering applications.
In a laminar flow in a pipe, the shear stress distribution refers to how the shear stress varies across the cross-section of the pipe. The shear stress is the force per unit area that acts parallel to the flow direction and it is caused by the viscosity of the fluid.
Understanding laminar flow
Laminar flow is a type of flow where the fluid particles move in parallel layers, with little mixing between the layers. It occurs at low flow velocities and is characterized by smooth and orderly flow patterns. In a pipe, the velocity of the fluid is highest at the center of the pipe and decreases towards the walls.
Shear stress distribution in laminar flow
The shear stress distribution in laminar flow can be determined by applying the principle of fluid mechanics. The shear stress at a given point is proportional to the velocity gradient perpendicular to the flow direction.
Maximum shear stress at the boundary
In laminar flow in a pipe, the maximum shear stress occurs at the boundary or wall of the pipe. This is because the fluid in contact with the wall has zero velocity due to the no-slip condition, which states that the fluid at the wall must have the same velocity as the wall. Therefore, the velocity gradient is highest at the wall, resulting in the highest shear stress.
Decreasing shear stress towards the center
As we move away from the wall towards the center of the pipe, the velocity of the fluid gradually increases. This leads to a decrease in the velocity gradient and consequently a decrease in the shear stress. The shear stress distribution follows a linear profile, with the maximum value at the wall and decreasing linearly to zero at the center of the pipe.
Explanation of the correct answer (Option B)
Option B states that the maximum shear stress occurs at the boundary and decreases linearly to zero. This is the correct answer because it accurately describes the shear stress distribution in laminar flow in a pipe. The shear stress is highest at the wall due to the no-slip condition and decreases towards the center of the pipe as the velocity gradient decreases.
Conclusion
In summary, in laminar flow in a pipe, the shear stress is maximum at the boundary or wall of the pipe and decreases linearly to zero towards the center of the pipe. This shear stress distribution is a result of the velocity gradient perpendicular to the flow direction. Understanding the shear stress distribution is important in analyzing fluid flow and designing pipe systems in various engineering applications.
Discharge Q in a triangular weir varies as:-- a)H
- b)H1.5
- c)H0.5
- d)H2.5
Correct answer is option 'D'. Can you explain this answer?
Discharge Q in a triangular weir varies as:-
a)
H
b)
H1.5
c)
H0.5
d)
H2.5
|
|
Pallabi Tiwari answered |
Discharge through a triangular notch/weir is given by:
Where,
H = height of liquid above apex of the notch
θ = Angle of notch
Cd = Coefficient of discharge
Which of the following is CORRECT about the viscosity of gas?- a)Inversely proportional to the temperature
- b)Increases with an increase in the temperature
- c)Independent of pressure
- d)Independent of temperature
Correct answer is option 'B'. Can you explain this answer?
Which of the following is CORRECT about the viscosity of gas?
a)
Inversely proportional to the temperature
b)
Increases with an increase in the temperature
c)
Independent of pressure
d)
Independent of temperature
|
|
Aarav Kulkarni answered |
As temperature increases, randomness in molecules also increases. This increase in randomness will result in increase in viscosity as viscosity of gas depends on randomness & collision of gas molecules.
Phenomenon: As a gas is heated, the movement of gas molecules increases and the probability that one gas molecule will collide with another gas molecule increases. In other words, increasing gas temperature causes the gas molecules to collide more often. This increases the gas viscosity because the transfer of momentum between stationary and moving molecules is what causes gas viscosity.
The centre of pressure on inclined immersed surface remains valid for the centre of pressure on vertical immersed surface, if the angle (θ) at immersed surface with liquid surface is:- a)0°
- b)45°
- c)90°
- d)30°
Correct answer is option 'C'. Can you explain this answer?
The centre of pressure on inclined immersed surface remains valid for the centre of pressure on vertical immersed surface, if the angle (θ) at immersed surface with liquid surface is:
a)
0°
b)
45°
c)
90°
d)
30°
|
|
Siddharth Bajaj answered |
Centre of Pressure on a Immersed surface from water surface is given by:
For vertical surface θ = 90°
So, the formula is valid for θ = 90°
An orifice is said to be large, if- a)the size of the orifice is large
- b)the velocity of the flow is large
- c)the available head of liquid is more than 5 times the height of orifice
- d)the available head of liquid is less than 5 times the height of orifice
Correct answer is option 'D'. Can you explain this answer?
An orifice is said to be large, if
a)
the size of the orifice is large
b)
the velocity of the flow is large
c)
the available head of liquid is more than 5 times the height of orifice
d)
the available head of liquid is less than 5 times the height of orifice
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Pallabi Chavan answered |
An orifice is a small aperture through which the fluid passes. The thickness of an orifice in the direction of flow is very small in comparison to its other dimensions. An orifice is said to be large, if the available head of liquid is less than 5 times the height of orifice.
The mechanical efficiency of an impulse turbine is generally between:- a) 73-75
- b)97-99
- c)48-50
- d)88-90
Correct answer is option 'B'. Can you explain this answer?
The mechanical efficiency of an impulse turbine is generally between:
a)
73-75
b)
97-99
c)
48-50
d)
88-90
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Sahil Mehra answered |
Mechanical efficiency of Impulse turbine is given by:
It generally varies between 97 to 99
Also, volumetric efficiency (ηv) = 97 to 99
Overall efficiency (ηo) = 85 to 90
The major loss of hydraulic energy in pipe flow occurs in long pipe due to:-- a)Sudden enlargement
- b)Friction
- c)Sudden contraction
- d)Gradual enlargement or contraction
Correct answer is option 'B'. Can you explain this answer?
The major loss of hydraulic energy in pipe flow occurs in long pipe due to:-
a)
Sudden enlargement
b)
Friction
c)
Sudden contraction
d)
Gradual enlargement or contraction
|
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Gauri Sarkar answered |
There are generally two types of losses occur in a pipe flow problem:
a) Major loss: Major head loss occurs due to friction, which is given by:
Where f = friction factor= 
b) Minor head loss: Minor head loss occurs due to:
1. Sudden enlargement
2. Sudden contraction
3. Due to pipe bends
4. head loss at the entrance and exit of pipe etc.
Pressure of 200 kPa is equivalent to the head of z metre of liquid having relative density 1.59. The value of z (m) is _____.- a)11.6
- b)11.82
- c)12.58
- d)13.14
Correct answer is option 'C'. Can you explain this answer?
Pressure of 200 kPa is equivalent to the head of z metre of liquid having relative density 1.59. The value of z (m) is _____.
a)
11.6
b)
11.82
c)
12.58
d)
13.14
|
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Lakshmi Datta answered |
200 kPa = 200,000 Pa
200,000 Pa = 200,000 N/m²
Pressure in liquids is calculate by the formula:
P = αgh
Where P = pressure, α = density, g = force of gravity, and h = height
Taking g = 10
αgh = 200,000
1590 x 10 x h = 200,000
h = 200,000/15900
h = 12.58 m
A centrifugal pump delivers a liquid when pressure rise in impeller is equal to _______- a)Kinetic head
- b)Velocity head
- c)Static head
- d)Manometric head
Correct answer is option 'D'. Can you explain this answer?
A centrifugal pump delivers a liquid when pressure rise in impeller is equal to _______
a)
Kinetic head
b)
Velocity head
c)
Static head
d)
Manometric head
|
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Raghavendra Goyal answered |
Manometric head is the head against which head is required to be produced by the pump to deliver water to the destination. Manometric head is higher than the sum of suction and delivery heads because it accounts for head losses due to friction.
is the equation to determine kinematic viscosity of liquids by- a)Redwood Viscometer
- b)Engler Viscometer
- c)Saybolt universal viscometer
- d)Newton Viscometer
Correct answer is option 'C'. Can you explain this answer?
is the equation to determine kinematic viscosity of liquids bya)
Redwood Viscometer
b)
Engler Viscometer
c)
Saybolt universal viscometer
d)
Newton Viscometer
|
|
Jaideep Malik answered |
The device used for measurement of viscosity is known as viscometer. According to Saybolt viscometer:
In an orifice used for flow measurement, the coefficient of velocity is always:- a)equal to unity
- b)a non-zero negative number
- c)less than unity
- d)greater than unity
Correct answer is option 'C'. Can you explain this answer?
In an orifice used for flow measurement, the coefficient of velocity is always:
a)
equal to unity
b)
a non-zero negative number
c)
less than unity
d)
greater than unity
|
|
Nikhil Majumdar answered |
Coefficient of velocity through orifice =ActualvelocityTheoreticalvelocity 
Vtheo > Vact
So, Cv is always less than 1.
A compound pipe of diameters d1, d2 and d3 having length l1, l2 and l3 respectively is to be replaced by an equivalent pipe of uniform diameter d and length l. The size of the equivalent pipe is given by- a)
- b)
- c)
- d)
Correct answer is option 'D'. Can you explain this answer?
A compound pipe of diameters d1, d2 and d3 having length l1, l2 and l3 respectively is to be replaced by an equivalent pipe of uniform diameter d and length l. The size of the equivalent pipe is given by
a)
b)
c)
d)
|
|
Anisha Chakraborty answered |
For pipes in series equivalent pipe is given by:
For pipes in parallel equivalent pipe is given by
The equation 
Zconstant is based on the following assumptions regarding the flow of fluid- a)steady, frictionless, incompressible along a streamline
- b)steady, frictionless, uniform along a streamline
- c)steady, incompressible, uniform along a streamline
- d)steady, frictionless, incompressible and uniform
Correct answer is option 'A'. Can you explain this answer?
The equation Zconstant is based on the following assumptions regarding the flow of fluid
Zconstant is based on the following assumptions regarding the flow of fluida)
steady, frictionless, incompressible along a streamline
b)
steady, frictionless, uniform along a streamline
c)
steady, incompressible, uniform along a streamline
d)
steady, frictionless, incompressible and uniform
|
|
Nidhi Patel answered |
The equation is Bernoulli’s equation. lt is based on following assumptions:
i) flow is steady
ii) fluid is incompressible
iii) fluid is non-viscous since viscous force has been neglected: and
iv) it is applicable to points along a streamline
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