Junior Engineer • 2025 • PAPER-III D (Technical Subject)
The process of artificially supplying water to land for agricultural purposes is called-
A)
Drainage
B)
Irrigation
C)
Evaporation
D)
Infiltration
Option B is correct: Irrigation.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
How does crop growth stage affect its water requirement?
A)
Water demand remains the same throughout the growth period
B)
The highest water demand is during the initial germination stage
C)
The peak water demand is usually during the flowering and fruiting stages
D)
Water demand is highest at the maturity stage
Option C is correct: The peak water demand is usually during the flowering and fruiting stages.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
If a river has a cross-sectional area of 30 m² and the velocity of flow is 2 m/s, what is the discharge?
A)
30 m/s
B)
50 m²/s
C)
60 m³/s
D)
90 m/s
Option C is correct: 60 m³/s.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
Why is the selection of a particular type of irrigation system highly dependent on soil type?
A)
Some soils absorb water too quickly, making certain methods inefficient
B)
All irrigation methods work equally well, regardless of soil type
C)
Soil type only affects crop growth, not the irrigation method
D)
Irrigation system selection is only based on water availability
Option A is correct: Some soils absorb water too quickly, making certain methods inefficient.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
Using Chezy’s formula, V = C√(RS). If C=50, R=1.8 m, and S=0.0005, find velocity V.
A)
2.5 m/s
B)
3.0 m/s
C)
2.68 m/s
D)
1.5 m/s
Option C is correct: 2.68 m/s.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
What is the main advantage of a watershed canal?
A)
Requires minimal cross-drainage structures
B)
Allows easy water flow to adjacent areas
C)
Does not require embankments
D)
Follows natural river flow
Option A is correct: Requires minimal cross-drainage structures.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
Which of the following is NOT a preventive measure for waterlogging?
A)
Using well-planned irrigation techniques
B)
Installing drainage systems
C)
Growing water-demanding crops in all seasons
D)
Using raised beds for planting
Waterlogging occurs when the soil becomes saturated with water, displacing air and hindering root respiration. To prevent this, measures must focus on controlling the amount of water entering the soil or increasing the rate at which it leaves.
- Option (a) 'Using well-planned irrigation techniques' (such as drip or sprinkler irrigation) prevents waterlogging by applying only the required amount of water, avoiding over-saturation.
- Option (b) 'Installing drainage systems' (such as surface or subsurface drains) is a primary preventive and corrective measure to remove excess water from the root zone.
- Option (d) 'Using raised beds for planting' improves aeration and allows excess water to drain away from the plant roots, preventing localized waterlogging.
- Option (c) 'Growing water-demanding crops in all seasons' is NOT a preventive measure. While water-demanding crops use more water, planting them in all seasons—regardless of rainfall patterns or soil drainage capacity—does not address the structural or systemic causes of waterlogging. In fact, if the soil is already prone to waterlogging, attempting to maintain high water levels for such crops can exacerbate the saturation of the water table in the surrounding area.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
What is the significance of the Base Period of a crop?
A)
It determines the time between sowing and harvesting
B)
It is the total period from first to last irrigation
C)
It defines the period of highest water demand in a crop cycle
D)
It represents the time taken for root development
Option B is correct: It is the total period from first to last irrigation.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
A trapezoidal canal has a bottom width of 4 m, depth of 2 m, and side slope of 1:1. What is the top width?
A)
6m
B)
8m
C)
10m
D)
12m
Option B is correct: 8m.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
If the flow in an irrigation canal is subcritical, what does it indicate?
A)
The flow is slow and controlled by downstream conditions
B)
The flow is fast and controlled by upstream conditions
C)
The canal is in supercritical flow
D)
The flow is always uniform
Option A is correct: The flow is slow and controlled by downstream conditions.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
The duty of water is defined as:
A)
The depth of water required per hectare
B)
The amount of water required per unit crop area
C)
The number of hectares irrigated per unit discharge
D)
The loss of water due to evapotranspiration
Option C is correct: The number of hectares irrigated per unit discharge.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
Which factor affects the selection of Manning’s coefficient for a canal?
A)
Water temperature
B)
Roughness of the canal bed and side slopes
C)
Water depth only
D)
Shape of the canal
Option B is correct: Roughness of the canal bed and side slopes.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
Which factor affects groundwater movement?
A)
Soil permeability
B)
Temperature variations
C)
Humidity levels
D)
Atmospheric pressure
Option A is correct: Soil permeability.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
What is the primary advantage of using lined canals over unlined canals?
A)
Increased seepage losses
B)
Reduced seepage losses and increased efficiency
C)
Easier maintenance of canal embankments
D)
Reduced flow velocity
Option B is correct: Reduced seepage losses and increased efficiency.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
A trapezoidal canal has a discharge of 10 m³/s. If the velocity is 2 m/s, what is the required cross-sectional area?
A)
2.5 m²
B)
5.0 m²
C)
10.0 m²
D)
15.0 m²
Option B is correct: 5.0 m².
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
Why is water requirement generally higher for crops grown in regions with high wind speeds?
A)
Wind reduces soil moisture content
B)
Wind increases evapotranspiration
C)
Wind increases the infiltration rate
D)
Wind prevents percolation losses
Option B is correct: Wind increases evapotranspiration.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
What is the hydraulic radius of a trapezoidal channel with: Bottom width b=6m, Depth h=3m, Side slope m=1
A)
1.86m
B)
2.12m
C)
2.54m
D)
2.86m
Option A is correct: 1.86m.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
What is the most effective method to detect waterlogging?
A)
Checking soil color
B)
Measuring soil moisture content
C)
Observing plant height
D)
Measuring wind velocity
Option A is correct: Checking soil color.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
Which crop season in India typically requires the highest irrigation?
A)
Kharif
B)
Rabi
C)
Zaid
D)
Monsoon
Option C is correct: Zaid.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
Why does excessive irrigation lead to a decline in crop productivity over time?
A)
It increases the nutrient availability in soil
B)
It promotes deeper root growth
C)
It causes waterlogging and soil salinity
D)
It accelerates crop maturation
Option C is correct: It causes waterlogging and soil salinity.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
Which factor does NOT directly influence the crop water requirement?
A)
Soil type
B)
Crop type
C)
Wind speed
D)
Crop market price
Option D is correct: Crop market price.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
A field has a length of 300 meters and a width of 150 meters. If 5 cm of irrigation water is applied, calculate the total volume of water required (in cubic meters).
A)
2250 m³
B)
1500 m³
C)
2500 m³
D)
3000 m³
Option A is correct: 2250 m³.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
A canal has a bed slope of 1 in 5000, what is the value of S?
A)
0.0001
B)
0.0002
C)
0.0005
D)
0.0010
Option C is correct: 0.0005.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
What is the primary assumption of Lacey’s silt theory?
A)
The canal should have a rectangular cross-section
B)
The canal reaches a stable section where no silting or scouring occurs
C)
The canal should have a high velocity to prevent sediment deposition
D)
The flow is always turbulent in all sections of the canal
Option B is correct: The canal reaches a stable section where no silting or scouring occurs.
Junior Engineer • 2025 • PAPER-III D (Technical Subject)
Which of the following is a disadvantage of flood irrigation?
A)
High efficiency
B)
High water loss due to evaporation
C)
Uniform water distribution
D)
Cost-effectiveness
Option B is correct: High water loss due to evaporation.
