← MES Jr. Grade
Past Questions
Which of the following plays significant role for fluid to flow in laminar type?
A)
Pressure
B)
Temperature
C)
Viscosity
D)
Quantity
Laminar flow is the smooth, orderly flow of a fluid in layers. The property that strongly influences whether flow remains laminar is viscosity, because higher viscosity resists relative motion between fluid layers and helps maintain orderly flow. Pressure drives the flow, but it does not specifically determine the laminar nature. Temperature may affect viscosity indirectly, and quantity alone is not the controlling factor here.
In normal conditions, the period for sludge digestion is
A)
10 days
B)
20 days
C)
30 days
D)
60 days
In conventional sewage treatment, sludge digestion under normal conditions typically takes about 30 days. This is the standard detention period used in digestion tanks for proper stabilization of sludge. 10 days and 20 days are generally too short for normal digestion, while 60 days is longer than the usual normal-condition period.
The maximum pressure to which a pipe is subjected during its operation is known as
A)
Working pressure
B)
Design pressure
C)
Pipe pressure
D)
Test pressure
The maximum pressure a pipe experiences under normal operating conditions is called the working pressure. Design pressure is the pressure used for selecting pipe thickness and safety margins, and test pressure is the higher pressure used during pressure testing before commissioning. 'Pipe pressure' is not the standard technical term here.
The difference of the top ofa bank and the full supply level in a canal is called
A)
Berm
B)
Free board
C)
Height of bank
D)
None of these
In canal engineering, the vertical difference between the top of the canal bank and the full supply level (FSL) is called the free board. It provides safety against overtopping due to waves, surges, or operational fluctuations. A berm is a horizontal strip of land left between two slopes or between a bank and excavation, and height of bank refers to the overall height of the bank, not specifically the difference from FSL to top of bank.
Which of the following phenomenon in a pipe flow is termed as water hammer ?
A)
The sudden rise of pressure in a long pipe due to sudden closure of valve
B)
The rise of a pressure in a pipe flow due to gradual closure of a valve
C)
The rise of negative pressure
D)
The zero pressure in a pipe flow
Water hammer is the pressure surge (or shock wave) created when a moving fluid in a pipe is suddenly forced to stop or change direction, typically by rapid valve closure. This causes a sudden rise in pressure in the pipe. Option (b) is incorrect because gradual closure produces a much smaller pressure change. Options (c) and (d) do not describe water hammer.
Any independent mass of fluid does not possess
A)
Elevation energy
B)
Kinetic energy
C)
Pressure energy
D)
None of these
An independent mass of fluid can possess elevation energy and kinetic energy. However, pressure energy is not associated with a fluid mass by itself in the same way; it is generally considered in a flowing fluid system as energy due to pressure. Hence, the correct answer is pressure energy.
The pressure intensity in kg/cm² at any point ina liquid is
A)
w
B)
wh
C)
wh
D)
h/w
Pressure intensity at a depth h in a liquid is given by p = w h, where w is the specific weight of the liquid. This is the standard hydrostatic pressure formula. Option (d) h/w is incorrect because pressure increases with specific weight and depth, not inversely. Option (a) w is only specific weight, not pressure. Hence the correct choice is (c) wh.
A multipurpose reservoir is the one which is
A)
Designed for one purpose but serves more than one purpose
B)
Planned and constructed to serve various purposes
C)
Both (a) and (b)
D)
None of these
A multipurpose reservoir is specifically designed from the beginning to fulfill more than one function, such as irrigation, flood control, hydropower generation, water supply, and recreation. Therefore, the correct definition is that it is planned and constructed to serve various purposes. Option (a) is not the standard definition because it suggests the reservoir was designed for one purpose and later serves others. Hence, (b) is correct and (c) cannot be correct because (a) is not accurate.
Gauge pressure is the same as
A)
Atmospheric pressure - absolute pressure
B)
Atmospheric pressure - vacuum
C)
Absolute pressure - atmospheric pressure
D)
Absolute pressure + atmospheric pressure
Gauge pressure is defined as the pressure measured relative to atmospheric pressure. Therefore,
Gauge pressure = Absolute pressure - Atmospheric pressure.
So option (c) is correct. Option (a) is incorrect because it reverses the terms. Option (b) is incorrect because vacuum pressure is not the same as atmospheric pressure minus vacuum in this context. Option (d) is incorrect because absolute pressure is not added to atmospheric pressure.
Higher yield may be expected from
A)
Gravity spring
B)
Surface spring
C)
Artesian spring
D)
All ofthese
An artesian spring is formed when confined groundwater under pressure rises naturally to the surface. Because it is pressurized and fed by a confined aquifer, it generally provides a more reliable and higher discharge than gravity springs or surface springs. Gravity springs depend on local seepage and usually have smaller yield, while surface springs are more limited and less dependable. Hence, higher yield may be expected from an artesian spring.
For providing an Indian type W.C, the RCC slabs in the toilet portion
A)
Should be sunk by 20 cm
B)
Should be sunk by 50 cm
C)
Should be kept 20 cm above the adjacent portion
D)
Need not be sunk
In an Indian type W.C., the toilet floor/slab portion is generally sunk below the adjacent floor level to accommodate the pan and ensure proper laying of pipes and waterproofing. The standard depth used in such exam questions is about 20 cm. Hence, option (a) is correct. The other options are incorrect because 50 cm is excessively deep, keeping it above the adjacent floor is the opposite of the required arrangement, and it cannot be left without sinking for an Indian type W.C.
Underground water is obtained from
A)
Rains
B)
Rivers
C)
Lakes
D)
Springs
Underground water is mainly formed by rainwater that infiltrates into the soil and percolates downward to recharge aquifers. Rivers and lakes can also recharge groundwater locally, but the primary source is rainfall. Springs are outlets where groundwater comes out to the surface, so they are not the source.
AGI pipe has coating of
A)
Zine
B)
Lead
C)
Silver
D)
Aluminium
AGI stands for Galvanized Iron pipe. Galvanization means coating iron or steel with zinc to prevent rusting and corrosion. So the correct coating is zinc (spelled as 'Zine' in the option). Lead, silver, and aluminium are not the standard coating used for GI pipes.
An aquifer that is confined at the bottom but not at the top is known as
A)
Partially confined aquifer
B)
Aquiclude
C)
Semi-confined aquifer
D)
Unconfined aquifer
An aquifer confined only at the bottom and open or only partly confined at the top is called a semi-confined aquifer, also known as a leaky aquifer. It receives some leakage through the upper confining layer. A partially confined aquifer is not the standard term here, an aquiclude is an impermeable confining layer, and an unconfined aquifer has no confining layer at the top.
Water supply system means
A)
Digging of well for water
B)
Construction of dams
C)
Construction of canals
D)
Entire arrangement from the source of supply to distribution
A water supply system includes all the components involved in providing water to users: source, collection, treatment, storage, transmission, and distribution. Therefore, the correct definition is the entire arrangement from the source of supply to distribution. Options (a), (b), and (c) mention only individual works, not the full system.
The change of physical property in isothermal process is governed by
A)
Reynold’s number
B)
Bernoulli’s equation
C)
Boyle’s Law
D)
Navier-Stokes equation
In an isothermal process, temperature remains constant. For a gas undergoing isothermal compression or expansion, pressure and volume vary inversely, so the change in physical property is governed by Boyle’s Law (P1V1 = P2V2). Reynold’s number relates to flow regime, Bernoulli’s equation relates pressure-velocity-energy in fluid flow, and Navier-Stokes equations describe fluid motion, not the isothermal gas law.
Gravel packing in underground water well
A)
Recharges the water level
B)
Reduces the percolation considerably
C)
Increases the specific capacity
D)
Reduces the effective diameter of well
Gravel packing around a well is used to improve the inflow of groundwater into the well by stabilizing the formation and reducing entrance losses. This increases the well’s yield per unit drawdown, i.e., its specific capacity. It does not recharge the water level, does not reduce percolation considerably, and it does not reduce the effective diameter of the well in a way that is the intended effect here.
Bernoulli’s equation assumes that
A)
Fluidis non-viscous
B)
Fluid is homogeneous
C)
Flowis steady
D)
All ofthese
Bernoulli’s equation is derived under ideal flow assumptions. It assumes the fluid is non-viscous, the flow is steady, and the fluid is homogeneous (incompressible for most civil engineering applications). Since all the listed conditions are part of the Bernoulli assumptions, the correct answer is 'All of these'. Options (a), (b), and (c) are each true individually, so they are not the best single answer.
In order to prevent settlement of the sewage solid in sanitary sewers, velocity required to be maintained is not less than ;
A)
0.4m/s
B)
0.6m/s
C)
0.75 m/s
D)
0.8m/s
In sanitary sewer design, a minimum self-cleansing velocity is maintained so that suspended sewage solids do not settle and cause choking. The commonly accepted minimum velocity is about 0.6 m/s. Hence, among the given options, 0.6 m/s is correct. The lower values 0.4 m/s and 0.75 m/s are not the standard minimum threshold used for preventing deposition, and 0.8 m/s is higher than necessary for the stated purpose.
The frictional resistance in the laminar flow is
A)
Not affected by the variation of temperature
B)
Dependant of pressure
C)
Proportional to the velocity of flow
D)
All ofthese
In laminar flow, the resisting shear stress is directly proportional to the velocity gradient, and for flow through a pipe the frictional resistance is proportional to the flow velocity. It is not generally stated as being dependent on pressure, and temperature affects viscosity, so option (a) is incorrect. Hence, the correct choice is (c).
Hydrostatic pressure on a dam depends upon its :
A)
Length
B)
Depth
C)
Shape
D)
Material
Hydrostatic pressure in a fluid at rest is given by p = ρgh, where h is the depth below the free surface. Therefore, the pressure on a dam increases with depth. It does not depend on the dam’s length, shape, or material for the pressure itself—though the total force on the dam depends on the area and distribution of pressure.
Balancing depth in irrigation canal section is
A)
Depth in which flow of water is optimum
B)
Depth in which cutting and filling will be equal
C)
Depth in which required side slope will be maintained
D)
Depth in which length of canal will be minimum
Balancing depth in a canal section is the depth at which the earthwork in excavation (cutting) equals the earthwork in embankment (filling). This makes the canal section economically balanced, with no surplus cut or fill. Option (a) refers to an optimum hydraulic depth, option (c) is about side slope design, and option (d) is unrelated to the definition of balancing depth.
In hydraulic jump, passage of water is
A)
Froma super critical state to sub-critical state
B)
From sub-critical state to super critical state
C)
From critical state to super critical state
D)
From sub-critical state to critical state
A hydraulic jump occurs when fast-moving shallow water (supercritical flow, Froude number > 1) suddenly transitions to slower-moving deeper water (subcritical flow, Froude number < 1). This causes a rapid rise in water depth and dissipation of energy. Hence, the passage of water is from supercritical state to subcritical state. The other options describe the reverse or incorrect transitions.
The retention time of septic tank at average daily flow is
A)
8 hours
B)
12 hours
C)
24 hours
D)
48 hours
The detention or retention time of a septic tank at average daily flow is generally taken as about 24 to 48 hours, and in standard exam practice the commonly accepted design value is 48 hours. This allows sufficient settling of solids and anaerobic digestion. 8 hours and 12 hours are too short for proper settling, while 24 hours is often considered the minimum range but not the usual exam answer for septic tank retention time.
A piezometer opening in pipe measures
A)
Velocity head
B)
Static pressure
C)
Total pressure
D)
Double static pressure
A piezometer is a simple vertical tube connected to a pipe. The liquid rises in it until the hydrostatic head balances the pressure at the tapping point, so it measures the **static pressure head** (pressure intensity) in the pipe. It does not measure velocity head or total pressure. Total pressure would require a stagnation device like a Pitot tube.