ā JE Departmental
Past Questions ā 2026
Which document is referred to for standard rates while preparing repair estimates?
A)
Log book
B)
Measurement book (MB)
C)
Tender Notice
D)
Schedule of Rates (SOR)
In civil engineering estimation and costing, the Schedule of Rates (SOR) is the official document published by government departments (such as the PWD or PHED) that lists the standardized rates for various items of work, materials, and labor for a specific region and time period. When preparing any estimate, including repair estimates, the SOR is used to ensure uniformity, transparency, and accuracy in cost calculation.
Why other options are incorrect:
- a. Log book: Used for recording the daily operation and maintenance history of machinery or equipment, not for pricing work.
- b. Measurement book (MB): The primary record where actual measurements of work executed on-site are recorded for payment purposes; it does not provide the rates themselves.
- c. Tender Notice: An invitation to contractors to bid for a project; it is a procurement document, not a reference for standard government rates.
What fuel is commonly used in a CI engine?
A)
Diesel
B)
Petrol
C)
Kerosene
D)
CNG
A CI engine stands for 'Compression Ignition' engine. In this type of engine, air is compressed to a very high pressure and temperature. Fuel is then injected into this hot compressed air, causing it to ignite spontaneously without the need for a spark plug. Diesel is the standard fuel used in CI engines because it has the appropriate volatility and ignition characteristics (cetane number) to ignite under these high-compression conditions.
Why other options are incorrect:
- b. Petrol: Used in SI (Spark Ignition) engines; it is too volatile and would ignite prematurely (knock) in a CI engine.
- c. Kerosene: While it can be used in some specialized or older engines, it is not the 'common' fuel and can cause carbon deposits and lubrication issues.
- d. CNG: Compressed Natural Gas is typically used in SI engines (spark-ignited) or dual-fuel systems, but not as the primary fuel for a standard CI engine.
Biodegradable waste includes:
A)
Plastic
B)
Glass
C)
Food waste
D)
Metal
Biodegradable waste refers to organic materials that can be broken down (decomposed) into simpler organic matter by the action of microorganisms such as bacteria and fungi.
1. Food waste (Option c) consists of organic matter (carbohydrates, proteins, fats) which is readily decomposed by microbes, making it biodegradable.
2. Plastic (Option a) is a synthetic polymer derived from petroleum; it is non-biodegradable because microorganisms lack the enzymes to break its strong carbon-carbon bonds.
3. Glass (Option b) is an inorganic material made primarily of silica; it is chemically inert and does not decompose biologically.
4. Metal (Option d) is an inorganic element/alloy; while it may corrode or oxidize (chemical change), it is not broken down by biological organisms.
Efficiency of pump is defined as the ratio of:
A)
input power to output power
B)
speed to torque
C)
head to discharge
D)
output power to input power
Efficiency (Ī·) of any mechanical system, including a pump, is defined as the ratio of the useful work performed (output) to the total energy supplied to the system (input).
1. In the context of a pump, the 'Output Power' is known as the Water Horsepower (WHP), which is the power actually delivered to the fluid to increase its pressure or lift it to a certain height.
2. The 'Input Power' is known as the Brake Horsepower (BHP), which is the power supplied to the pump shaft by the motor or engine.
Formula: Efficiency (Ī·) = (Output Power / Input Power) Ć 100%
Analysis of other options:
- Option (a) is the inverse of efficiency; input power is always greater than output power due to losses (friction, leakage), so this ratio would be > 1.
- Option (b) Speed to torque is not a definition of efficiency; their product (Speed Ć Torque) is actually proportional to power.
- Option (c) Head to discharge is a characteristic of the pump's performance curve, not a measure of efficiency.
The main purpose of flux in welding is to:
A)
increase welding speed
B)
increase hardness of weld
C)
reduce power consumption
D)
prevent oxidation of molten metal
In welding, flux is a chemical cleaning agent, flowing agent, or purifying agent. Its primary function is to protect the weld pool from atmospheric contamination. When flux melts, it forms a protective layer (slag) over the molten metal, which prevents oxygen and nitrogen from the air from reacting with the molten metal (oxidation). This prevents the formation of porosity and inclusions, ensuring a strong, clean weld.
Analysis of other options:
- (a) Welding speed is primarily determined by the current, voltage, and the skill of the operator, not the flux.
- (b) Hardness is generally controlled by the base metal composition, filler metal chemistry, and the cooling rate (heat treatment), not the flux itself.
- (c) Power consumption is a function of the electrical parameters of the welding machine and the material thickness, and is not reduced by the use of flux.
The structure used to collect water from a river is called:
A)
Reservoir
B)
Aqueduct
C)
Intake
D)
Weir
Step-by-step reasoning: 1. The objective is to identify the structure specifically designed to collect or withdraw water from a raw water source (like a river) for treatment and distribution. 2. An 'Intake' structure is specifically engineered to draw water from a river, lake, or reservoir while preventing debris and fish from entering the pumping system. 3. Analysis of other options: (a) A Reservoir is a large natural or artificial lake used for storage, not the specific collection structure. (b) An Aqueduct is a conduit or bridge-like structure used to transport water from one location to another. (d) A Weir is a low dam built across a river to raise the water level or measure flow, which may facilitate an intake, but the weir itself is not the collection structure. Therefore, 'Intake' is the correct technical term.
If pump efficiency decreases, required power will:
A)
decrease
B)
remain same
C)
increase
D)
become zero
To understand this, we must look at the relationship between Water Power (Hydraulic Power) and Brake Power (Shaft Power).
1. Water Power (P_w) is the theoretical power required to lift a certain volume of fluid to a specific height: P_w = Ļ * g * Q * H (where Ļ is density, g is gravity, Q is flow rate, and H is head).
2. Brake Power (P_b) is the actual power input required from the motor to drive the pump.
3. Pump Efficiency (Ī·) is defined as the ratio of Water Power to Brake Power: Ī· = P_w / P_b.
Rearranging the formula to find the required power (Brake Power): P_b = P_w / Ī·.
Since the Water Power (P_w) remains constant for a given flow and head, the Brake Power (P_b) is inversely proportional to the efficiency (Ī·). Therefore, if the efficiency decreases (Ī· ā), the required input power must increase (P_b ā) to maintain the same output.
- Option (a) is incorrect because a decrease in efficiency means more energy is lost (as heat or vibration), requiring more input, not less.
- Option (b) is incorrect because power input must change to compensate for efficiency losses.
- Option (d) is incorrect because zero power would mean the pump is not operating.
The recommended velocity of flow for pumping mains is generally:
A)
0.1 ā 0.3 m/s
B)
0.6 ā 1.5 m/s
C)
2.5 ā 4 m/s
D)
above 5 m/s
In water supply and pumping systems, the velocity of flow in pumping mains is determined by balancing two competing factors: the cost of the pipe (capital cost) and the cost of energy to overcome friction (operational cost).
1. If the velocity is too low (e.g., 0.1 ā 0.3 m/s), the pipe diameter must be very large to carry the required discharge, leading to excessively high material and installation costs.
2. If the velocity is too high (e.g., above 2.5 m/s), the head loss due to friction increases exponentially (since head loss is proportional to the square of the velocity, hf ā vĀ²). This leads to high pumping costs and increases the risk of water hammer (hydraulic transients) which can burst the pipes.
Therefore, the economically and technically optimal velocity range for pumping mains is generally accepted to be between 0.6 m/s and 1.5 m/s. This range ensures that the pipes are not oversized while keeping friction losses and energy consumption within reasonable limits.
Black smoke from a diesel engine indicates:
A)
excess air supply
B)
proper combustion
C)
incomplete combustion
D)
low fuel supply
In a diesel engine, black smoke is primarily composed of unburnt carbon particles (soot). This occurs when there is an insufficient supply of oxygen to completely oxidize the fuel injected into the cylinder, or when the fuel is not atomized properly. This condition is known as 'incomplete combustion'.
Analysis of options:
- (a) Excess air supply: This would lead to leaner combustion and typically results in clear exhaust or, in some cases, white/blue smoke if oil is leaking, but not black smoke.
- (b) Proper combustion: Ideal combustion results in colorless or nearly colorless exhaust gases (mostly CO2, H2O, and N2).
- (c) Incomplete combustion: Correct. A rich fuel-to-air ratio (too much fuel or too little air) prevents the carbon in the fuel from burning completely, resulting in black soot.
- (d) Low fuel supply: This would lead to a lean mixture, which generally prevents the formation of black smoke and may cause the engine to lose power or stall.
The most common material used for septic tank construction is:
A)
Timber
B)
Steel sheet
C)
RCC
D)
Plastic
A septic tank is an underground anaerobic digestion chamber that must be completely watertight to prevent groundwater contamination and withstand external soil pressure.
1. **RCC (Reinforced Cement Concrete)**: This is the most common material because it provides the necessary structural strength to resist earth pressure, is naturally impermeable (when properly cast), and is highly durable against the corrosive gases (like Hydrogen Sulfide) produced during the decomposition of sewage.
2. **Timber**: This is unsuitable as it decays rapidly in moist, underground environments and is not watertight.
3. **Steel sheet**: While strong, steel is highly susceptible to corrosion due to the acidic nature of sewage and the moist soil environment, making it impractical for long-term underground use.
4. **Plastic**: While some prefabricated plastic tanks exist for small-scale residential use, RCC remains the standard and most common material for general engineering construction of septic tanks due to its longevity and load-bearing capacity.
The main purpose of a service reservoir is:
A)
Water treatment
B)
Storage and distribution
C)
Pumping
D)
Filtration
A service reservoir (also known as a distribution reservoir) is a critical component of a water supply system located between the treatment plant and the consumers. Its primary purposes are: 1) Storage: To balance the difference between the constant rate of water supply from the treatment plant and the fluctuating hourly demand of the consumers (peak demand vs. average demand). 2) Distribution: To provide sufficient hydraulic head (pressure) to ensure water reaches all parts of the distribution network, especially when using elevated service reservoirs (ESRs).
Why other options are incorrect:
- a. Water treatment: This occurs at the Water Treatment Plant (WTP) before the water reaches the service reservoir.
- c. Pumping: While pumps may be used to fill a reservoir, the reservoir itself is a storage structure, not a pumping mechanism.
- d. Filtration: This is a specific process within the treatment stage (e.g., rapid sand filters) and is not the function of a service reservoir.
The purpose of chlorination is:
A)
Disinfection
B)
Softening
C)
Sedimentation
D)
Aeration
Chlorination is the addition of chlorine to water primarily to kill or inactivate disease-causing microorganisms, so its main purpose is disinfection. Option b is incorrect because softening removes hardness-causing calcium and magnesium ions, not germs. Option c is incorrect because sedimentation is the settling of suspended particles by gravity. Option d is incorrect because aeration is the process of bringing water into contact with air to remove gases, improve taste/odor, or oxidize certain impurities.
What is the main purpose of maintaining a logbook in a Water Supply System?
A)
To record personal attendance
B)
To track daily weather report
C)
To record operational data and performance of system
D)
Sedimentation tank
In Water Supply Management, a logbook serves as the primary official record for the operation and maintenance (O&M) of the system. Its main purpose is to document critical operational data such as pump running hours, flow rates, pressure readings, chemical dosage (e.g., chlorine), water levels in reservoirs, and any breakdowns or repairs. This data is essential for analyzing system performance, predicting maintenance needs, and ensuring accountability.
Analysis of other options:
- Option (a) 'To record personal attendance' is the purpose of an attendance register, not a system logbook.
- Option (b) 'To track daily weather report' may be a secondary observation in some contexts, but it is not the 'main purpose' of a water supply operational logbook.
- Option (d) 'Sedimentation tank' is a physical component of a water treatment plant, not a purpose for maintaining a record book.
HDPE pipes are preferred because they are:
A)
Corrosion resistant
B)
Brittle
C)
Heavy
D)
Expensive
High-Density Polyethylene (HDPE) pipes are widely preferred in public health engineering and water distribution systems due to several key material properties:
1. **Corrosion Resistance (Correct):** HDPE is a chemically inert thermoplastic. Unlike metallic pipes (such as cast iron or galvanized steel), it does not rust or corrode when exposed to moisture, soil chemicals, or various corrosive fluids. This significantly increases the lifespan of the piping system and reduces maintenance costs.
2. **Ductility vs. Brittleness (Incorrect):** HDPE is known for its flexibility and toughness. It is the opposite of 'brittle'; it can withstand significant deformation and ground movement without cracking.
3. **Weight (Incorrect):** HDPE is lightweight compared to concrete or metal pipes, making it easier and cheaper to transport and install.
4. **Cost (Incorrect):** While initial material costs vary, HDPE is generally considered cost-effective over its lifecycle due to lower installation costs (fewer joints) and lack of need for expensive anti-corrosion coatings.
Multistage centrifugal pumps are used to obtain:
A)
high discharge
B)
high head
C)
pumping of viscous fluids
D)
high head and high discharge
A centrifugal pump is a kinetic machine that converts rotational energy into pressure energy. The head (pressure) developed by a single-stage centrifugal pump is limited by the impeller diameter and the rotational speed. To achieve a higher head without increasing the speed to impractical levels or making the impeller excessively large, multiple impellers are arranged in series. In a multistage centrifugal pump, the discharge of the first stage becomes the suction for the second stage, and so on. Consequently, the total head produced is the sum of the heads produced by each individual stage (Total Head = n Ć Head per stage, where n is the number of stages).
Why other options are incorrect:
- (a) High discharge: To increase discharge (flow rate), pumps are typically arranged in parallel, or a larger impeller diameter is used in a single stage.
- (c) Pumping of viscous fluids: Centrifugal pumps are generally inefficient for high-viscosity fluids; positive displacement pumps are used for that purpose.
- (d) High head and high discharge: While some pumps can do both, the specific defining purpose of 'multistaging' (series arrangement) is specifically to increase the head.
Which maintenance practice most effectively improves the service life of the induction motor bearings?
A)
Increasing supply voltage
B)
Regular lubrication
C)
Increasing cooling air
D)
Reducing starting current
Induction motor bearings fail mainly due to friction, heat, and wear. Regular lubrication reduces friction and overheating, prevents metal-to-metal contact, and therefore most effectively extends bearing service life. Increasing supply voltage can damage the motor, increasing cooling air helps temperature but does not directly protect bearings as effectively as lubrication, and reducing starting current is beneficial for the motor generally but is not the primary maintenance practice for bearing life.
After maintenance shutdown, line-to-line voltages are measured at the control panel using a voltmeter. Which of the following electrical abnormalities can be identified using this measurement?
A)
Overcurrent of the motor windings
B)
Misalignment of the motor
C)
Insulation failure of motor windings
D)
Missing phase in the supply
Line-to-line voltage measurement at a control panel is used to check the presence and balance of all three phases. If one phase is missing, the line-to-line readings will show an abnormal or absent voltage pattern. Overcurrent, motor misalignment, and insulation failure are not directly identified by this voltage measurement; they require current, mechanical, or insulation tests.
Which of the following is a pipe appurtenance?
A)
Beam
B)
Sluice valve
C)
Column
D)
Slab
A pipe appurtenance is a fitting or accessory used with pipelines to control, regulate, or maintain flow. A sluice valve is a common pipe appurtenance because it is installed in pipelines to stop or allow water flow. Beam, column, and slab are structural members, not pipe appurtenances.
The first step in planning a water supply scheme is:
A)
Pump selection
B)
Survey and investigation
C)
Reservoir construction
D)
Pipe laying
In water supply planning, the first step is to conduct a survey and investigation to assess the source, demand, topography, population, and water quality. Only after this data is collected can the system be properly designed. Pump selection, reservoir construction, and pipe laying are later implementation stages, not the starting step.
The most suitable pump for deep bore wells is:
A)
Centrifugal pump
B)
Reciprocating pump
C)
Submersible pump
D)
Air lift pump
A deep bore well requires a pump that can work at great depth, remain submerged, and lift water efficiently from below ground level. A submersible pump is designed for this purpose because it is installed inside the bore well below the water level. Centrifugal pumps are generally used for low to moderate lift and are not suitable for deep bore wells. Reciprocating pumps are not preferred for such applications due to complexity and limited discharge. Air lift pumps can be used in special conditions, but they are not the most suitable general choice for deep bore wells.
The structure used to collect water from a river is called:
A)
Reservoir
B)
Aqueduct
C)
Intake
D)
Weir
An intake structure is specifically built to collect or withdraw water from a source such as a river, lake, or reservoir for water supply. Hence, the correct answer is (c) Intake. A reservoir is a storage structure, an aqueduct is a channel or bridge for conveying water, and a weir is a barrier built across a river to raise or control water level.
Why is insulation resistance measured before energizing electrical machines?
A)
To measure efficiency
B)
To confirm polarity
C)
To reduce starting current
D)
To avoid electrical faults
Insulation resistance is measured before energizing electrical machines to check the condition of insulation between windings and between windings and earth. A low insulation resistance may indicate moisture, aging, contamination, or damaged insulation, which can cause leakage current, short circuits, shock hazard, or equipment failure. Therefore, this test is done to avoid electrical faults. The other options are incorrect because efficiency is not determined by insulation resistance, polarity is checked by separate tests, and starting current is unrelated to insulation resistance measurement.
GI pipe stands for:
A)
Galvanized Iron
B)
Ground Iron
C)
General Iron
D)
Grey Iron
GI pipe stands for Galvanized Iron pipe. It is an iron/steel pipe coated with zinc to resist corrosion. The other options are incorrect because Ground Iron, General Iron, and Grey Iron are not the standard meaning of GI in piping materials.
Storm water drains are designed to carry:
A)
Rainwater runoff
B)
Sewage
C)
Industrial effluent
D)
Sludge
Storm water drains are meant to collect and convey rainwater runoff from roads, rooftops, and open surfaces during rainfall. They are not designed for sewage, industrial effluent, or sludge, which require separate conveyance and treatment systems.
When a current-carrying conductor is placed in a magnetic field, it experiences:
A)
Mechanical Force
B)
Change in resistance
C)
Magnetic Flux
D)
Electric Shock
A current-carrying conductor placed in a magnetic field experiences a force due to the interaction between the magnetic field and the current. This is known as the motor effect. Therefore, the correct answer is Mechanical Force. The other options are incorrect because the conductor does not necessarily undergo a change in resistance, it does not experience magnetic flux itself, and electric shock is not the direct effect described here.