Q.1) The maximum application rate by sprinklers is limited by –
A) The infiltration capacity
B) The prevailing wind velocity
C) The quantity of water available
D) Sprinkler irrigation
Option (A)
Explanation :
The maximum application rate by sprinklers is limited by the infiltration capacity of the soil. In this method water is applied in the form of spray as an ordinary rain.
This method is useful where –
i) Land cannot be prepared for surface methods.
ii) Slope is excessive and topography is irregular.
iii) Soil is errosive.
Q.2) Absolute humidity in air –
A) Increases at higher altitudes
B) Decreases at higher altitudes
C) Remains constant at all altitudes
D) Increases at all altitudes
Option (B)
Explanation :
The measure of absolute water vapour in air is called Absolute Humidity.
When the air is lifted, the water vapour as well as the air expands, thereby decreasing the moisture volume proportinately. Thus, absolute humidity decreases as the air is lifted.
Q.3) The most suitable method of irrigation for areas having low rainfall and strong winds is –
A) Sprinkler irrigation
B) Drip irrigation
C) Furrow irrigation
D) Free flooding
Option (B)
Explanation :
Drip irrigation is one of the popular methods of irrigtion and is being largely used in areas with acute scarcity of irrigation water and salt problem.
In this method, water is slowly and directly applied to root zone of the plants, in order to minimize the losses due to evaporation and percolation.
This method is best suited for raw crops and orchards such as tomatoes, grapes, corn etc.
Q.4) In Furrow Irrigation the depth of furrows from ground level is kept as –
A) 40 to 50 cm
B) 5 to 10 cm
C) 10 to 20 cm
D) 20 to 30 cm
Option (D)
Explanation :
The depth of furrows may vary from 20 to 30 cm for soil of low permeability.
The common size of furrow for row crops such as cotton, tobacco and potatoes is about 25 cm wide and 8 to 10 cm deep.
Q.5) An infiltration gallery is used to obtain water from –
A) a well sink in a river bed
B) a trench dug in a river bed
C) perforated pipe laid in a trench in a river bed
D) impounded reservoir
Option (C)
Explanation :
Underground constructions known as infiltration galleries are made to collect stormwater and allow it to seep into the ground. In order to collect and store runoff or extra water that gathers during rain or snowmelt events, they are often built beneath the soil at the base of a hill. The groundwater table can then be refilled with this runoff, which can subsequently be used for a variety of things, including irrigation and drinking water.
Water from an infiltration gallery has the advantage of bank filtration to reduce the water treatment requirements for a surface withdrawal.
Q.6) The Gross Command Area (GCA) for a distributary in 6000 ha, 80% of which is ulturable irrigable. The intensity of irrigation for Kharif season is 25%. The area to be irrigated in Kharif season is _____ ha.
A) 600
B) 1200
C) 2400
D) 4800
Option (B)
Explanation :
Culturable Command Area, CCA = 80% of GCA = (80/100)*6000 = 4800 ha.
Intensity of irrigation = 25% (given)
Area to be irrigated = (25/100)*4800 = 1200 ha.
Q.7) With the increase in quantity of water supplied, yield of most crops –
A) continuously increases
B) continuously decreases
C) increases up to a certain limit
D) decreases up to a certain limit
Option (C)
Explanation :
The yield of most crops increases upto a certain limit and decreases with increase in quantity of water supplied.
The amount of water required for complete growth of crop is known as kor depth, this water fulfilled by rain and irrigation.
Q.8) One of the advantages of lining water canals for irrigation is –
A) increases channel cross-section
B) increases seepage of water
C) helps increase the command area
D) increases potential chances of breaching
Option (C)
Explanation :
Advantages of Canal Lining :
i) Water carrying capacity increases
ii) Seepage reduction
iii) Prevention of water logging
iv) Low maintenance
v) Safety against floods
Q.9) If moisture tension for a soil is 15 atm, then the soil is at –
A) Field capacity
B) Permanent wilting point
C) Optimum moisture content
D) Equivalent moisture
Option (B)
Explanation :
Soil moisture tension is a measurement of the amount of effort required to extract water from soil. The higher the soil moisture tension, the harder it is for plants to absorb water.
Soil Moisture Tension at Field Capacity : 1/10 to 1/3 atm.
Soil Moisture Tension at Permanent Wilting Point : 7 to 32 atm.
Q.10) Which instrument is used to measure the precipitation in the regions of difficult and inaccessible terrains?
A) Radar
B) Float type rain gauge
C) Weighing bucket rain gauge
D) Siphon rain gauge
Option (A)
Explanation :
Rain, snow, and hail are all types of precipitation that can be detected and measured using radar. Microwave signals are used by weather radar systems to identify the kind, location, and intensity of precipitation, giving vital data for weather forecasting and severe weather warnings.
“Radio Detection and Ranging” is what radar stands for. It is a system that detects the presence, location, and movement of objects using radio waves and then relays that information to a receiver. Numerous uses for radar exist, including traffic management, weather forecasting, military surveillance and targeting, and air and sea navigation. Even in bad weather or low visibility, radar can offer real-time information on the range, speed, and direction of objects by generating a radio signal and analysing the reflected waves.
Q.11) Rainfall simulators are used to determine –
A) Avg. rainfall depth
B) Infiltration capacity
C) Rainfall potential of a storm
D) Rainfall intensity
Option (A)
Explanation :
A system or instrument used to replicate rain for testing or research is known as a rain simulator. Simple settings, like spraying water on a test subject, can be used as a rain simulator, as can more sophisticated setups that produce a controlled environment with adjustable rain intensity, droplet size, and dispersion.
These simulators are frequently employed in a variety of industries, including transportation engineering, where they can be used to evaluate the effectiveness of rain sensors, windscreen wipers, and other systems that are exposed to the elements.
They are also used in meteorology to research the physical processes involved in precipitation and rain generation, as well as in agriculture to examine the effects of rain on crops and soil.
Q.12) What is the major source of atmospheric moisture for precipitation?
A) Evaporation from wells
B) Evaporation from ponds
C) Evaporation from rivers
D) Evaporation from oceans
Option (D)
Explanation :
Nil.
Q.13) The process by which the rain water enters the surface of earth is called –
A) Seepage
B) Infiltration
C) Percolation
D) Absorption
Option (B)
Explanation :
Seepage: The slow flow of water through small cracks or porous material.
Infiltration: The entry of water into the soil from the surface.
Percolation: The movement of water through soil, rock, or other porous material.
Absorption: The process by which a liquid is taken into a porous material or dissolved into a solvent.
Q.14) Unit hydrograph method for flood estimation is applied to –
A) Hilly areas
B) Small basins
C) Medium & Large basins
D) All of the above
Option (D)
Explanation :
In hydrology, a unit hydrograph is a hydrographic tool that is used to show how rain affects streamflow or runoff. It is a graph that depicts the link between a watershed’s runoff volume and the amount of time that has passed since a rainfall event.
The unit hydrograph, under the assumption that all other factors remain constant, represents the typical reaction of a watershed to a rainfall event of a given duration and intensity. It is used to design water management systems, such as stormwater detention facilities and drainage networks, and to forecast the rate and amount of runoff for a specific storm event.
Q.15) The hydrograph of short duration can be converted into hydrograph of longer duration by –
A) S-curve method
B) Unit hydrograph
C) Synthetic unit hydrograph
D) Flood routing
Option (A)
Explanation :
The S-curve hydrograph is a particular type of hydrograph that shows how streamflow or runoff gradually increases and decreases in response to a rainfall event. The hydrograph with an S-curve exhibits a more progressive reaction that accounts for the lag time between water infiltration into the soil and the slow discharge of water from the watershed. Because of the rising limb of the graph’s “S” form, the S-curve is so named.
This shape is a result of the steady rise in runoff that occurs as water percolates through the soil, reaches the groundwater table, and starts to flow into rivers and streams. The S-curve hydrograph is used to create stormwater management plans and model how a watershed reacts to rainfall.
Using S-curve we can convert D hour unit hydrograph into T hour unit hydrograph.
Q.16) A 60% index of wetness means –
A) rain excess of 40%
B) rain deficiency of 60%
C) rain deficiency of 40%
D) None of the above
Option (C)
Explanation :
Wetness index + rain deficiency = 100%
rain deficiency = 100% – 60% = 40%
Hence, rain deficiency of 40%.
Q.17) Muckingham’s method is connected to which of the following :
A) Flood routing
B) Infiltration capacity
C) Design flood estimation
D) Unit hydrograph
Option (A)
Explanation :
A hydrological approach called the Muskingum method is used to simulate how flood flows will move through a river or stream system. It is a form of numerical technique that simulates the flow of water through a system of channels and reservoirs using a combination of calculus and linear algebra.
Based on the conservation of mass principle, the Muskingum technique makes the assumption that the change in flow at every point in the river system is proportionate to the difference in water levels upstream and downstream of that location.
Q.18) If the total accumulated precipitation of the storm is plotted against time, the curve is known as –
A) Mass curve
B) Rain hydrograph
C) Intensity duration frequency curves
D) Depth area duration curve
Option (A)
Explanation :
Mass curve: A mass curve is a graph that represents the cumulative volume of water in a watershed over time. It is used to describe the amount of water that enters a watershed from precipitation and the amount of water that leaves the watershed as runoff. The mass curve is a useful tool for understanding the water balance in a watershed and for designing water management systems.
Rain hydrograph: A rain hydrograph shows the relationship between rainfall intensity and time for a specific storm event. It is used to represent the distribution of rainfall over time for a specific storm and to estimate the runoff response to that storm.
Intensity-Duration-Frequency (IDF) curves: IDF curves are graphs that display the correlation between a location’s specific rainfall intensity, duration, and frequency. They are used in the design of stormwater management systems, such as drainage networks and detention facilities, to estimate the expected rainfall intensity for various durations and frequency of occurrence.
Depth-Area-Duration (DAD) curve: DAD curves are used to estimate the runoff response to a specific storm event and to design stormwater management systems. The DAD curve provides information on the expected runoff volume for different rainfall depths, areas, and durations, and can be used to design detention facilities and drainage networks.
Q.19) Which method gives accurate estimate of average rainfall in hilly area catchment?
A) Arithmetic mean method
B) Isohyetal method
C) Normal ratio method
D) Theissen polygon method
Option (B)
Explanation :
Isohyetal Method is superior of all methods, as it is a line joining points of equal rainfall magnitude.
Q.20) Precipitation caused by lifting of air mass due to pressure difference is called –
A) Orographic precipitation
B) Cyclonic precipitation
C) Convective precipitation
D) Frontal Precipitation
Option (B)
Explanation :
Cyclonic Precipitaion : Caused by lifting of air mass.
Frontal Precipitation : Caused due to lifting of warmer air over colder.
Orographic Precipitation : Caused due to mountain barriers thereby undergo condensation and precipitation.
Convective Precipitation : Causes due to lifting of warmer air packet surrounded by colder air packets due to lower density.
