← MES Jr. Grade
Past Questions
In an area where the danger of waterlogging has become imminent :-
A)
Further canal irrigation should be introduced
B)
No further canal irrigation should be introduced
C)
The area should be irrigated by Tube wells
D)
Both (b) & (c) are recommended
Waterlogging occurs when the water table rises too close to the ground surface, usually due to excessive canal seepage and over-irrigation. In such an area, further canal irrigation should not be introduced because it can worsen the problem. Instead, tube wells are preferred since they help lower the groundwater table by pumping out water. Therefore, both stopping further canal irrigation and using tube wells are correct.
Which of the following is viral type of waterborne disease :-
A)
Salmonellosis
B)
Giardiasis
C)
Poliomyelitis
D)
Shigellosis
Waterborne diseases can be caused by bacteria, protozoa, or viruses. Poliomyelitis is a viral disease caused by poliovirus and can spread through contaminated water. In contrast, Salmonellosis is bacterial, Giardiasis is caused by a protozoan parasite, and Shigellosis is bacterial.
The type of plastic generally used for indoor fire sprinkler system since it is suited for use with both hot water and pressurized water is :-
A)
PVC Pipe
B)
UPVC Pipe
C)
CPVC Pipe
D)
PE Pipe
CPVC (Chlorinated Polyvinyl Chloride) is generally used for indoor fire sprinkler systems because it can withstand both hot water and pressurized water. PVC and UPVC are less suitable for higher-temperature hot water applications, while PE is not the standard choice for indoor fire sprinkler piping.
Slipper bearing in lubrication mechanics is an example of :-
A)
Laminar flow between two fixed plates
B)
Couette flow
C)
A curved surface lubricant film
D)
Dash-Pot mechanism
A slipper bearing (shoe bearing) works with a thin lubricant film between a curved moving surface and a stationary surface, so it is an example of lubrication over a curved surface. It is not flow between two fixed plates, and it is not the standard Couette flow case of parallel plates. A dash-pot is a damping device, not a bearing lubrication model.
A linear reservoir is one in which :-
A)
the volume varies linearly with elevation
B)
the storage varies linearly with the outflow rate
C)
the storage varies linearly with time
D)
the storage varies linearly with the inflow rate
A linear reservoir is defined by a linear storage-discharge relationship, i.e., storage S is directly proportional to outflow Q. Hence, as outflow changes, storage changes linearly with it. Option (a) refers to a storage-elevation relationship, and (c) and (d) are not the defining properties of a linear reservoir.
Specific capacity in connection with Ground water is :-
A)
a constant for a given well
B)
depends on aquifer characteristics only
C)
increases with discharge rate
D)
decreases with time from the start of pumping
Specific capacity of a well is the discharge per unit drawdown (Q/s). As pumping continues, drawdown usually increases due to cone of depression and aquifer losses, so the ratio Q/s generally decreases with time. Hence it is not a constant for a well, not dependent on aquifer characteristics only, and not something that increases with discharge rate.
Choose the wrong statement from the following in connection with waterlogging in irrigation engineering-
A)
Drainage becomes impossible and CO2 cannot be dissolved
B)
The roots of the plants are confined to the top layers soil above the water-Table
C)
Soil remains warm thus bacterial action becomes sluggish
D)
There is accumulation of alkali salts in the surface soil
Waterlogging means the soil becomes saturated with water and air circulation in the root zone is poor. Because of this, drainage is hampered, carbon dioxide accumulates, and roots remain confined to the upper soil layers above the water table. It also often leads to accumulation of harmful salts in the surface soil. However, the statement that the soil remains warm and therefore bacterial action becomes sluggish is wrong; in waterlogged soil, poor aeration and often lower soil temperature generally reduce microbial activity.
In one complete revolution of the crank in double acting pump, there will be :-
A)
One suction and one delivery stroke
B)
Two suction strokes and one delivery stroke
C)
Two suction strokes and two delivery strokes
D)
One suction stroke and two delivery strokes
In a double-acting pump, water is delivered on both sides of the piston. So, during one complete revolution of the crank, the pump performs two suction strokes and two delivery strokes. Option (a) is for a single-acting pump, not a double-acting pump.
The minimum velocity in sewers to be maintained in order to prevent settlement of sewage solid in the system is :-
A)
0.4 m/s
B)
0.6 m/s
C)
0.8 m/s
D)
0.9 m/s
In sewer design, a minimum self-cleansing velocity is maintained so that suspended solids do not settle and cause blockage. The commonly accepted minimum velocity is about 0.6 m/s. Hence option (b) is correct. The other values are either too low to prevent deposition reliably or are above the standard minimum requirement.
The Ozone depleting potential of Dichlorotetrafluoroethane (C2F4Cl2) is :-
A)
0.6
B)
0.8
C)
1.0
D)
10.0
Dichlorotetrafluoroethane (C2F4Cl2), also known as CFC-114, has an ozone depletion potential (ODP) of about 0.6 relative to CFC-11 (which is taken as 1.0). Therefore, option (a) is correct. The other options do not match the standard ODP value for this compound.
Choose the odd one out from the following water works system :-
A)
Pipe lines
B)
Aqueducts
C)
Open Channels
D)
Tunnels
In a water works system, pipe lines, aqueducts, and tunnels are all generally closed/conveyance structures used to transport water. Open channels, on the other hand, carry water exposed to the atmosphere, so they are the odd one out.
If the pressure surface of Aquifer lies above the ground surface, the well will be :-
A)
Artesian well
B)
Non-artesian well
C)
Non-flowing artesian well
D)
Flowing artesian well
If the pressure surface (piezometric surface) of a confined aquifer lies above the ground surface, water rises in the well and flows out naturally without pumping. This is called a flowing artesian well. An artesian well in general may or may not flow, but when the pressure surface is above ground level, it specifically becomes a flowing artesian well. Non-artesian wells are not under confined pressure, and non-flowing artesian wells have the pressure surface below ground level.
If in a flow-mass curve, a demand line drawn tangent to the lowest in a valley of the curve does not intersect the mass curve at an earlier time period, it represents that :-
A)
the reservoir is full at the beginning of the dry period
B)
the reservoir is wasting water by spill
C)
the storage is inadequate
D)
the reservoir will not be full at the start of the dry period
In a flow-mass curve, a demand line tangent to the lowest point in a valley indicates the minimum storage condition needed to meet demand. If this tangent does not intersect the mass curve at an earlier time, it means there was not enough preceding inflow to fill the reservoir up to the required level before the dry period begins. Hence, the reservoir will not be full at the start of the dry period. Option (b) would apply if the demand line lay below the mass curve causing spill, while (a) and (c) do not match the tangent/no-earlier-intersection condition.
Choose the wrong statement from the following in connection with Bligh’s creep theory :-
A)
the outer edges of faces of end sheet piles are much more effective than the inner ones
B)
There is no explanation about the requirements of exit gradient
C)
The theory holds good as long as the horizontal distance between the pile lines is greater than twice their depths
D)
There is no distinction between horizontal and vertical creep
Bligh’s creep theory assumes that seepage follows the contact surface and gives equal weight to horizontal and vertical creep; it also does not properly explain exit gradient. The statement about horizontal distance between pile lines being greater than twice their depths belongs to Lane’s weighted creep concept, not Bligh’s theory. Therefore, option (c) is the wrong statement. Options (a), (b), and (d) are consistent with Bligh’s creep theory.
The most common cause of acidity in water is :-
A)
CO
B)
CO2
C)
NO
D)
H3
The most common cause of acidity in water is carbon dioxide (CO2). When CO2 dissolves in water, it forms carbonic acid (H2CO3), which lowers the pH and makes the water acidic. CO is not the usual cause of acidity, NO is not a direct common cause, and H3 is not a relevant standard chemical species in this context.
For a given inflow rate in a reservoir :-
A)
trap efficiency increases with the reduction in reservoir capacity
B)
trap efficiency decreases with the increase in reservoir capacity
C)
trap efficiency decreases with the reduction in reservoir capacity
D)
there is no correlation between trap efficiency and reservoir capacity
Trap efficiency is the fraction of incoming sediment retained by a reservoir. For a given inflow rate, a larger reservoir generally has more storage and a longer detention time, so it can trap more sediment. Therefore, when reservoir capacity is reduced, the ability to retain sediment falls and trap efficiency decreases. Hence, option (c) is correct. Options (a) and (b) state the opposite relationship, and (d) is incorrect because trap efficiency does correlate with reservoir capacity.
According to Kennedy’s theory the quantity of silt transported is given by Q=aBV5/2 where a is the constant, the value of a as determined by Kennedy is :-
A)
0.5 to 0.4
B)
0.9 to 0.8
C)
1.1 to 1.2
D)
Not determined by Kennedy
Kennedy’s silt transport relation is commonly written in the form Q = a B V^(5/2), where a is an empirical constant. Kennedy determined the value of a approximately in the range 0.8 to 0.9. Therefore, the correct option is (b) 0.9 to 0.8. The other options are incorrect because 0.5–0.4 and 1.1–1.2 do not match Kennedy’s recommended constant, and Kennedy did determine this constant experimentally.
The Capacity factor of hydro-power plant will be identical with the load factor when :-
A)
Peak load is less than plant capacity
B)
Peak load equals to plant capacity
C)
Peak load is less than utilization factor
D)
Peak load equals to utilization factor
Capacity factor = (average load / plant capacity) and load factor = (average load / peak load). These two become identical when the denominator is the same in both expressions, i.e., when peak load equals plant capacity. Then both ratios reduce to average load / plant capacity. Option (a) is not necessary for equality, and (c) and (d) are incorrect because utilization factor is not the condition for equality here.
In sedimentation tanks if the horizontal velocity is just sufficient to produce scour then :-
A)
the particles will be carried to the outlet before settling
B)
the particles will be resuspended
C)
scouring will happen at the bottom of the tank
D)
the flow pattern will minimize the effect of inlet and outlet disturbances
In a sedimentation tank, if the horizontal velocity is just sufficient to produce scour, the flow becomes strong enough to disturb the settled or settling particles and lift them back into suspension. That is called scouring/resuspension. Option (a) is about particles being carried to the outlet, which depends on insufficient settling time, not scour. Option (c) is too general and refers to scouring at the bottom, but the key effect described is the resuspension of particles. Option (d) refers to hydraulic design to reduce inlet/outlet disturbances, not scour.
Fire hydrants are classified as one-way, two-way, three-way and four-way depending upon :-
A)
The number of hose outlets provided
B)
The number of hose inlets provided
C)
The type of valve of the gate
D)
The diameter of the hydrant
Fire hydrants are classified as one-way, two-way, three-way, and four-way based on the number of hose outlets available for connecting fire hoses. A one-way hydrant has one outlet, a two-way hydrant has two, and so on. The other options are incorrect because hydrants are not classified by hose inlets, valve type, or diameter.
Air vessel in reciprocation pump is provided to :-
A)
have continuous uniform rate supply of liquid from a single acting pump
B)
have a uniform rate of liquid in delivery stroke for a single acting pump
C)
have both (a) & (b)
D)
prevent possible air lock during operation of the pump
An air vessel in a reciprocating pump serves two main purposes: (1) it makes the discharge more uniform by providing a continuous, nearly steady supply of liquid from a single-acting pump, and (2) it helps maintain a more uniform rate of liquid flow during the delivery stroke. Therefore, both statements (a) and (b) are correct. Option (d) is incorrect because preventing air lock is not the primary function of an air vessel in a reciprocating pump.
The name D.Thoma of Germany in connection with hydraulic turbine is associated with :-
A)
Performance curves
B)
Efficiency
C)
Specific turbine
D)
Cavitation
D. Thoma of Germany is associated with cavitation in hydraulic turbines. He introduced the concept of Thoma's cavitation coefficient, which is used to predict cavitation conditions. The other options are incorrect because performance curves relate to turbine testing, efficiency is a general performance measure, and specific turbine is not linked to Thoma's name.
Choose the correct answer from the following :-
A)
Turbine with highest permissible specific speed is not preferable
B)
Higher specific speed turbine is generally more liable to cavitations
C)
Turbine with higher specific speed will be relatively bigger in size
D)
Higher the specific speed of turbine, higher will be the relative costs
Specific speed is the speed of a geometrically similar turbine that would produce unit power under unit head. As specific speed increases, the turbine generally operates at lower head and higher discharge, which increases the risk of cavitation. Therefore, statement (b) is correct.
Why others are incorrect:
(a) A higher permissible specific speed can actually be desirable depending on the application; the statement is not generally true.
(c) Higher specific speed turbines are usually more compact, not bigger in size.
(d) Higher specific speed does not necessarily mean higher relative cost; in fact, compact high-specific-speed turbines may be economical in suitable conditions.
In hydro-electric power plant, a passage of gradually increasing cross-sectional area connecting the runner exit to the tail race is :-
A)
Scroll casing
B)
Governor
C)
Draft-tube
D)
Runs and platforms
In a hydro-electric power plant, the passage of gradually increasing cross-sectional area connecting the runner exit to the tail race is called a draft tube. It helps recover kinetic energy from water leaving the runner and improves turbine efficiency. Scroll casing distributes water to the runner, the governor controls turbine speed, and runs/platforms are not relevant parts of the turbine passage.
In order to accelerate the flow of compressible fluid at super-sonic velocity, the flow passage must :-
A)
remain a uniform cross-section
B)
converge
C)
diverge
D)
flow passage does not have any effect
For compressible flow at supersonic speed, increasing velocity requires a diverging passage. In a converging nozzle, subsonic flow accelerates, but supersonic flow decelerates. Therefore, to accelerate a supersonic compressible fluid, the flow passage must diverge. Option (a) is incorrect because a uniform area does not provide the necessary acceleration mechanism. Option (b) is incorrect because convergence accelerates subsonic flow, not supersonic flow. Option (d) is incorrect because the passage shape clearly affects compressible-flow velocity.