← JE Departmental
Past Questions
The aggregate impact value of aggregate to be used in water bound macadam base course is-
A)
less than or equal to 35%
B)
less than or equal to 40%
C)
less than 45%
D)
more than 30%
The Aggregate Impact Value (AIV) is a measure of the resistance of an aggregate to sudden shock or impact. In highway engineering, the permissible limits for AIV depend on the type of pavement layer and the traffic volume. For a Water Bound Macadam (WBM) base course, the standard specification (as per IRC - Indian Roads Congress) generally stipulates that the aggregate impact value should not exceed 40%.
Breakdown of options:
- Option (a) 'less than or equal to 35%' is typically required for wearing courses (surface courses) where the impact and abrasion are higher.
- Option (b) 'less than or equal to 40%' is the standard requirement for base courses like WBM.
- Option (c) 'less than 45%' is too lenient for a standard base course.
- Option (d) 'more than 30%' is logically incorrect as specifications always set a maximum upper limit (ceiling) for impact values to ensure strength, not a minimum lower limit.
What is quantity of cement in 1cum of Cement mortar 1:3?
A)
495 kgs
B)
525kgs
C)
400kgs
D)
510kgs
To calculate the quantity of cement in 1 cubic meter (cum) of cement mortar 1:3, we follow these steps:
1. **Determine the Dry Volume**: When water is added to cement and sand, the volume shrinks. To get 1 cum of wet/compacted mortar, we need a dry volume of approximately 1.33 to 1.35 times the wet volume.
Dry Volume = 1.33 × 1.0 = 1.33 cum.
2. **Calculate the Sum of Proportions**:
Ratio = 1:3
Sum = 1 + 3 = 4.
3. **Calculate Volume of Cement**:
Volume of Cement = (Ratio of Cement / Sum of Proportions) × Dry Volume
Volume of Cement = (1 / 4) × 1.33 = 0.3325 cum.
4. **Convert Volume to Mass (Weight)**:
The density of cement is approximately 1440 kg/m³.
Mass of Cement = Volume × Density
Mass of Cement = 0.3325 × 1440 = 478.8 kg.
*Note on Variation*: In many standard engineering textbooks and PWD specifications, a dry volume factor of 1.37 or a slightly different density/wastage factor is used. If we use a dry volume factor of 1.375:
Volume = (1/4) * 1.375 = 0.34375 cum
Mass = 0.34375 * 1440 = 495 kg.
Comparing this to the options provided, 495 kgs is the standard calculated value used in many competitive exams for this specific ratio. Options b, c, and d do not align with the standard dry volume calculations for a 1:3 mix.
Dry lean concrete is used in concrete pavement as-
A)
wearing course
B)
base course
C)
subgrade
D)
sub-surface drainage
Dry Lean Concrete (DLC) is a low-strength concrete mix with a low water-cement ratio, designed to provide a stiff, stable, and uniform support layer for the main concrete pavement slab. In the structural hierarchy of a rigid pavement, the DLC acts as the 'base course' (or sub-base), sitting between the subgrade/granular sub-base and the Pavement Quality Concrete (PQC) wearing course.
Why other options are incorrect:
- a. Wearing course: This is the top layer exposed to traffic, typically made of Pavement Quality Concrete (PQC) in rigid pavements, which requires high strength and durability.
- c. Subgrade: This is the natural soil or compacted earth layer at the very bottom of the pavement structure.
- d. Sub-surface drainage: This refers to systems (like perforated pipes or filter materials) used to remove water from the pavement layers, not a structural concrete layer.
Proper grading of aggregates in concrete improves-
A)
Workability
B)
Slump
C)
Density
D)
Setting time of concrete
Grading refers to the particle size distribution of aggregates. Proper grading (well-graded aggregates) ensures that smaller particles fill the voids between larger particles. This reduction in void space leads to a more compact mass, which directly increases the density of the concrete. A denser concrete typically requires less cement paste to fill the gaps, resulting in higher strength and lower permeability.
Why other options are incorrect:
- a. Workability: While grading affects workability, it is not the primary goal of grading. In fact, very well-graded concrete can sometimes be less workable than gap-graded concrete if the surface area is too high.
- b. Slump: Slump is a measure of workability, not a property improved by grading itself; it is primarily controlled by the water-cement ratio and admixtures.
- d. Setting time: Setting time is a chemical property of the cement paste (hydration process) and is not influenced by the physical grading of the aggregates.
What is the code of practice for Design loads (other than earthquake) for buildings and structures, Dead loads-unit weights of building material and stored material?
A)
IS 456 2000
B)
IS 456 1987
C)
IS 875 1987 Part 1
D)
IS 1950-1962
The question asks for the specific Indian Standard (IS) code governing design loads, specifically dead loads and unit weights of materials.
1. **IS 875 (Part 1): 1987** is the official Code of Practice for 'Design loads (other than earthquake) for buildings and structures - Part 1: Dead Loads'. It provides the unit weights of various building materials (like concrete, steel, masonry) and stored materials used to calculate the self-weight of a structure.
2. **IS 456: 2000** (Option a) is the 'Plain and Reinforced Concrete - Code of Practice'. While it references loads, its primary purpose is the design and detailing of concrete structures.
3. **IS 456: 1987** (Option b) is an older version of the concrete code, not the primary code for general design loads.
4. **IS 1950: 1962** (Option d) relates to the 'Code of practice for design and construction of reinforced concrete retaining walls', which is a specialized structural code rather than a general load code.
Therefore, IS 875 Part 1 is the correct and authoritative standard for dead loads.
Finer the cement, the need for water for hydration and workability-
A)
Reduces
B)
Same for all size of cement
C)
Reduces to great extent
D)
Increases
The fineness of cement refers to the average size of the cement particles. When cement is finer, it has a larger total surface area per unit mass. This affects the water requirement in two ways: 1. Hydration: Since hydration is a surface chemical reaction, a larger surface area allows water to react with the cement particles more rapidly, increasing the rate of hydration. 2. Workability: To maintain the same level of workability (fluidity), more water is required to wet the increased surface area of the finer particles. If the water content is not increased, the mix becomes stiffer and less workable. Therefore, as the fineness of cement increases, the demand for water for both hydration and workability also increases.
The maximum stress of concrete is reached at a strain approximately equal to-
A)
0.003
B)
0.03
C)
0.002
D)
0.02
In concrete technology and reinforced concrete design (based on IS 456:2000 and ACI standards), the stress-strain curve for concrete in compression is non-linear. The maximum compressive stress (peak stress) is typically reached at a strain of approximately 0.002. After this point, the concrete enters a softening phase where the stress decreases as the strain increases until it reaches the ultimate failure strain (which is typically taken as 0.003 or 0.0035 depending on the code).
- Option (a) 0.003: This is generally considered the ultimate strain at failure, not the strain at maximum stress.
- Option (b) 0.03: This value is far too high for concrete, which is a brittle material.
- Option (d) 0.02: This value is also too high and exceeds the failure limit of concrete.
What is quantity of cement in 1cum of Cement mortar 1:4?
A)
400kgs
B)
340kgs
C)
380kgs (Building SOR 19 analysis)
D)
420kgs
To calculate the quantity of cement in 1 cubic meter (cum) of cement mortar 1:4, we follow these steps:
1. **Dry Volume Calculation**: When water is added to cement and sand, the volume shrinks. To get 1 cum of wet (finished) mortar, we need a larger volume of dry materials. For cement mortar, a shrinkage factor of approximately 1.30 to 1.33 is typically used.
Dry Volume = 1.33 × 1.0 = 1.33 cum.
2. **Ratio Sum**: The mix ratio is 1:4. Total parts = 1 + 4 = 5.
3. **Volume of Cement**:
Volume of cement = (1 / 5) × 1.33 = 0.266 cum.
4. **Weight of Cement**:
The density of cement is approximately 1440 kg/m³.
Weight = 0.266 × 1440 ≈ 383 kg.
**Analysis of Options**:
- While theoretical calculations yield ~383 kg, the question explicitly mentions '(Building SOR 19 analysis)'.
- In Schedule of Rates (SOR) provided by government departments (like CPWD or State PWDs), constants are standardized based on empirical field data and specific waste allowances.
- According to the standard analysis used in many Building SORs for 1:4 mortar, the quantity is standardized to **380 kgs**.
- Options a, b, and d do not align with the standard SOR analysis for a 1:4 mix.
The unit of strain is-
A)
mm
B)
N/sqmm
C)
Mpa
D)
Dimensionless
Strain is defined as the ratio of the change in dimension (deformation) to the original dimension of a body. Mathematically, Strain (ε) = ΔL / L, where ΔL is the change in length and L is the original length. Since both the numerator and the denominator are measured in the same units of length (e.g., mm/mm or m/m), the units cancel each other out. Therefore, strain is a dimensionless quantity and has no unit.
Analysis of other options:
- Option (a) 'mm' is a unit of length, used for deformation (ΔL), not strain.
- Option (b) 'N/sqmm' is a unit of stress (Force/Area).
- Option (c) 'Mpa' (Megapascal) is also a unit of stress or pressure (1 MPa = 1 N/mm²).
A cement bag of 50 kg in litre is approximately-
A)
30 litre
B)
35 litre
C)
40 litre
D)
42 litre
To find the volume of a 50 kg bag of cement in litres, we use the standard density of Ordinary Portland Cement (OPC).
1. **Standard Density of Cement**: The bulk density of cement is generally taken as 1440 kg/m³.
2. **Calculation of Volume in Cubic Meters**:
Volume = Mass / Density
Volume = 50 kg / 1440 kg/m³ ≈ 0.03472 m³
3. **Conversion to Litres**:
Since 1 cubic meter (m³) = 1000 litres,
Volume in litres = 0.03472 m³ × 1000 L/m³ = 34.72 litres.
4. **Approximation**: The value 34.72 litres is approximately 35 litres.
Therefore, a 50 kg bag of cement occupies approximately 35 litres of volume.
When bars of two different diameters are to be spliced, the lap length should be calculated on the basis of-
A)
Larger diameter bars
B)
Both the diameters together
C)
Smaller diameter bars
D)
Diameter of standard bar
In Reinforced Cement Concrete (RCC) design, splicing (lapping) is used to transfer stress from one bar to another through the surrounding concrete via bond stress. When two bars of different diameters are spliced, the strength of the joint is limited by the capacity of the smaller bar. Specifically, the smaller bar is the 'weak link' in the connection; if the lap length were calculated based on the larger bar, the smaller bar might fail to develop its full yield strength before pulling out of the concrete. Therefore, to ensure that the smaller bar can safely transfer its entire load to the larger bar, the lap length is calculated based on the diameter of the smaller bar. This is a standard practice in structural codes (such as IS 456 or ACI) to ensure the continuity of reinforcement based on the minimum cross-sectional area involved in the splice.
Night soil collection refers to:
A)
Manual collection of human waste
B)
Storage of rainwater
C)
Collection of grey water
D)
Water sample testing
Step-by-step reasoning: 1. Definition: In the context of sanitation and environmental engineering, 'night soil' is a traditional term used to describe human excreta (feces and urine) that is collected from pit latrines or buckets. 2. Process: 'Night soil collection' refers to the practice of removing this waste, typically during the night or early morning hours to minimize public nuisance and odor, for disposal or use as fertilizer. 3. Evaluating Options: Option (a) correctly identifies this as the collection of human waste. Option (b) refers to rainwater harvesting. Option (c) refers to grey water (wastewater from baths, sinks, and washing machines, excluding toilets). Option (d) refers to water quality analysis. Therefore, option (a) is the only technically correct answer.
Which one of the following is a reinforced material?
A)
Plain Cement Concrete
B)
Brick
C)
Reinforced Cement Concrete
D)
Stone
A reinforced material is a composite material consisting of a matrix (the bulk material) and a reinforcement (usually fibers or bars) to improve its mechanical properties, specifically to increase tensile strength.
1. **Reinforced Cement Concrete (RCC)**: Concrete is very strong in compression but weak in tension. To overcome this, steel bars (reinforcement) are embedded in the concrete. The combination of concrete (matrix) and steel (reinforcement) makes it a reinforced material. This is the correct answer.
2. **Plain Cement Concrete (PCC)**: This consists only of cement, aggregates, and water. It lacks any internal reinforcement and is therefore not a reinforced material.
3. **Brick**: This is a ceramic material made from fired clay. It is a homogeneous material (in terms of structural composition) and not reinforced.
4. **Stone**: This is a natural geological material. While it has internal mineral structures, it is not a 'reinforced material' in the engineering sense of adding a secondary material to enhance properties.
Which one of these is not a component of rural sanitation?
A)
Soak pit
B)
Night soil disposal
C)
Septic tank
D)
Storm water drain
Rural sanitation primarily focuses on the management of human excreta and wastewater (greywater) to prevent disease and environmental contamination.
1. Soak pits (Option a) are used for the disposal of effluent from septic tanks or greywater in rural areas.
2. Night soil disposal (Option b) refers to the collection and removal of human excreta from pit latrines, a key aspect of sanitation management.
3. Septic tanks (Option c) are onsite wastewater treatment systems commonly used in rural settings where centralized sewerage is unavailable.
In contrast, Storm water drains (Option d) are designed to manage surface runoff from rain. While they are a part of general civil infrastructure and urban drainage systems, they are categorized under 'Drainage' or 'Hydrology' rather than 'Sanitation' (which specifically deals with waste and hygiene). Therefore, storm water drainage is not a component of the sanitation cycle focused on waste disposal.
Population forecasting using Arithmetic increase method is suitable for:
A)
Cities with rapid growth
B)
Small towns, slow growth
C)
Developing cities
D)
Decreasing trend in growth
The Arithmetic Increase Method assumes that the population increases by a constant amount each decade, regardless of the current population size.
1. **Why Option (b) is correct**: This method is most suitable for old, established cities or small towns where the growth rate has stabilized and is slow. In such cases, the population growth is linear rather than exponential.
2. **Why Option (a) and (c) are incorrect**: Cities with rapid growth or developing cities typically experience exponential or geometric growth. For these, the Geometric Increase Method or the Incremental Increase Method is used, as these methods account for the compounding effect of population growth.
3. **Why Option (d) is incorrect**: While the arithmetic method can technically be used for a decreasing trend (negative constant increase), it is specifically designed to forecast steady, slow growth in stable urban environments, not specifically to model declining populations.
Motion of a piston inside a cylinder is an example of:
A)
Translatory (linear) motion
B)
Rotary motion
C)
Oscillatory motion
D)
Circular motion
In a reciprocating engine (such as an internal combustion engine), the piston is constrained by the cylinder walls to move back and forth along a straight line. This type of motion, where every point of the body moves in a parallel straight line, is defined as translatory or linear motion.
Analysis of other options:
- Rotary motion: This involves movement around a fixed axis (e.g., the crankshaft of the engine).
- Oscillatory motion: While the piston moves back and forth, 'oscillatory' typically refers to a swinging motion about a pivot point (like a pendulum).
- Circular motion: This involves movement along a circular path (e.g., the motion of the crank pin).
Therefore, the specific motion of the piston itself is translatory.
Which of the following is not a type of masonry work?
A)
Brick
B)
Stone
C)
RCC
D)
Laterite
Masonry is defined as the building of structures from individual units, usually called masonry units, which are laid in and bound together by mortar.
1. Brick Masonry (Option a): Uses bricks as the primary unit. It is a standard type of masonry.
2. Stone Masonry (Option b): Uses natural stones (rubble or ashlar) as the primary unit. It is a standard type of masonry.
3. Laterite Masonry (Option d): Uses laterite stone (a soil type rich in iron and aluminum) cut into blocks. It is a common type of masonry, especially in tropical regions.
4. RCC (Reinforced Cement Concrete) (Option c): RCC is a composite material made of concrete (cement, sand, aggregate, and water) reinforced with steel bars. It is a cast-in-place or pre-cast monolithic material, not a system of laying individual units with mortar. Therefore, it is classified as a concrete structure, not masonry work.
HDPE pipes are mostly preferred for:
A)
Electrical wiring
B)
Portable water supply due to flexibility
C)
Sewer lines only
D)
Road construction
HDPE (High-Density Polyethylene) pipes are widely preferred for potable water supply systems for several technical reasons: 1. Flexibility: They can bend to accommodate terrain changes, reducing the number of joints required. 2. Corrosion Resistance: Unlike metal pipes, HDPE does not rust or corrode, making it ideal for transporting drinking water. 3. Durability: It is resistant to chemical degradation and impact. 4. Leak-proof joints: Heat-fused joints create a monolithic system that prevents leakage.
Analysis of other options:
- Option (a): While HDPE can be used as conduits for electrical cables, it is not the 'most preferred' use case in the context of Public Health Engineering (PHE) piping materials.
- Option (c): While HDPE can be used for sewers, it is not used 'only' for sewer lines; its primary advantage in PHE is often water distribution.
- Option (d): HDPE is a piping material, not a primary material for road construction (which uses bitumen, concrete, etc.).
The daily clear water demand of rural area having a population of 420 souls at water supply level of 55 lpcd is:
A)
25,000 litres
B)
28,500 litres
C)
23,100 litres
D)
2,30,000 litres
To calculate the daily clear water demand, we use the following formula:
Daily Water Demand = Population × Per Capita Water Supply Rate
Given data:
1. Population = 420 souls
2. Water supply level (Per capita demand) = 55 lpcd (litres per capita per day)
Calculation:
Daily Demand = 420 souls × 55 litres/soul/day
Daily Demand = 23,100 litres/day
Comparing this result with the given options:
- Option (a) 25,000 litres is incorrect.
- Option (b) 28,500 litres is incorrect.
- Option (c) 23,100 litres matches our calculation exactly.
- Option (d) 2,30,000 litres is incorrect (likely a decimal placement error).
Therefore, the correct answer is 23,100 litres.
Which of the following pipe materials is corrosion-resistant?
A)
DI
B)
CI
C)
HDPE
D)
ERW
To determine which material is corrosion-resistant, we must analyze the chemical properties of each option:
1. **DI (Ductile Iron):** While stronger and more flexible than cast iron, DI is still a metallic material prone to oxidation and corrosion when exposed to moisture and soil chemicals. It usually requires internal linings (like cement mortar) and external coatings (like zinc or bitumen) to resist corrosion.
2. **CI (Cast Iron):** Like DI, cast iron is a ferrous metal. It is highly susceptible to corrosion (rusting) and tuberculation over time, especially in acidic or salty environments.
3. **HDPE (High-Density Polyethylene):** This is a thermoplastic polymer. Plastics are non-conductive and chemically inert to most acids, bases, and salts. Because it does not oxidize or rust, HDPE is inherently corrosion-resistant and is widely used in corrosive soil conditions or for transporting chemicals.
4. **ERW (Electric Resistance Welded Steel):** ERW refers to the manufacturing process of steel pipes. Steel is highly susceptible to corrosion and requires extensive galvanization or coating to prevent rust.
Conclusion: HDPE is the only non-metallic material listed, making it the only inherently corrosion-resistant option.
Rainwater harvesting does not include:
A)
Roof catchment
B)
Ground recharge pit
C)
Desalination plant
D)
Storage tank
Rainwater harvesting (RWH) is the process of collecting, filtering, and storing rainwater for future use or recharging groundwater.
1. Roof catchment (Option a): This is the most common method of RWH where the roof surface acts as the collection area.
2. Ground recharge pit (Option b): This is a key component of RWH used to direct harvested water into the aquifer to raise the water table.
3. Storage tank (Option d): This is used to store harvested rainwater for immediate or future domestic/agricultural use.
4. Desalination plant (Option c): Desalination is the process of removing salts and minerals from saline water (usually seawater or brackish water) to produce fresh water. It is a water production technology, not a rainwater harvesting technique, as it does not involve the collection of precipitation.
Which parameter is not considered in the design of pumping mains?
A)
Head
B)
Flow rate
C)
Efficiency
D)
Turbidity
The design of pumping mains (the pipelines that transport fluid from a pump to its destination) focuses on hydraulic performance and mechanical requirements.
1. **Head (Option a):** This is critical. Total Dynamic Head (TDH) includes static head and friction losses. It determines the pressure the pump must generate to move the fluid through the main.
2. **Flow rate (Option b):** This is fundamental. The design flow rate (discharge) determines the diameter of the pipe to ensure velocity stays within acceptable limits to prevent excessive friction loss or water hammer.
3. **Efficiency (Option c):** Pump and system efficiency are essential for calculating power requirements, operational costs, and selecting the appropriate pump model.
4. **Turbidity (Option d):** Turbidity refers to the cloudiness or haziness of a fluid caused by individual particles. While turbidity is a critical parameter for water *treatment* and *quality* analysis, it is not a hydraulic design parameter for the sizing or pressure calculations of the pumping main itself. Unless the fluid is highly viscous or abrasive (which is a different property than turbidity), turbidity does not affect the hydraulic design of the pipe.
The most commonly adopted pumps in water supplies are:
A)
centrifugal pumps
B)
reciprocating pumps
C)
rotary pumps
D)
submersible pumps
In water supply engineering, centrifugal pumps are the most commonly adopted pumps due to several key advantages: 1. High Discharge Capacity: They can handle large volumes of water, which is essential for municipal water distribution. 2. Simplicity: They have fewer moving parts compared to reciprocating pumps, leading to lower maintenance costs and higher reliability. 3. Steady Flow: They provide a continuous, non-pulsating flow of water. 4. Cost-Effectiveness: For the head and flow rates typically required in water supply systems, they are more economical to install and operate.
Comparing other options:
- Reciprocating pumps (b) are positive displacement pumps used for very high heads but low discharge; they produce pulsating flow and are too maintenance-intensive for general water supply.
- Rotary pumps (c) are typically used for high-viscosity fluids (like oils) rather than water.
- Submersible pumps (d) are a specific application/category of pumps (often using centrifugal impellers) used for deep wells, but 'centrifugal pumps' is the broader, more fundamental classification of the technology most widely used across all water supply stages (intake, treatment, and distribution).
Which type of intake is commonly used in rivers?
A)
Wet intake
B)
Direct pumping intake
C)
Ground intake
D)
Infiltration intake
In water supply engineering, intake structures are designed to withdraw water from a source (like a river, lake, or reservoir) and convey it to a treatment plant.
1. **Direct Pumping Intake (Option b):** This is a common method used in rivers where pumps are installed directly at the intake structure to lift water from the riverbed or water column and pump it directly to the treatment plant. It is efficient for rivers where the water level is relatively stable or where a pumping station can be constructed on the bank.
2. **Wet Intake (Option a):** While 'wet wells' are used in pumping stations, 'wet intake' is not a standard classification for a type of river intake structure in the same way direct pumping or infiltration galleries are.
3. **Ground Intake (Option c):** This is a generic term and not a standard technical classification for river intake structures.
4. **Infiltration Intake (Option d):** Also known as infiltration galleries, these are used when the river water is highly turbid or when the riverbed consists of permeable sand/gravel. While used in rivers, they are a specialized type of intake used for pre-filtration rather than the 'common' general-purpose intake used for bulk water withdrawal.
Therefore, among the given options, direct pumping is the most common general method for river water abstraction.
MLD in water supply stands for:
A)
Multi Litres per day
B)
Maximum litres per day
C)
Millilitres per day
D)
Million litres per day
In water supply and wastewater engineering, MLD is a standard unit of measurement used to quantify the capacity of water treatment plants, the volume of water demanded by a city, or the flow rate of a distribution system.
1. 'M' stands for Million (10^6).
2. 'L' stands for Litres.
3. 'D' stands for Day.
Therefore, 1 MLD = 1,000,000 litres of water per 24-hour period.
Analysis of other options:
- Option (a) 'Multi Litres' is not a recognized technical term in hydraulics.
- Option (b) 'Maximum litres' refers to a peak value, not a unit of measurement.
- Option (c) 'Millilitres' is a very small unit (1/1000 of a litre) and is not used to measure municipal water supply volumes.