Questions
21
The amount of irrigation water required to meet the evapotranspiration needs of the crop during its full growth is called
Answer: consumptive irrigation requirement
22
With the increase in the quantity of water supplied, the yield of most crops
Answer: increases upto a certain limit and then decreases
23
If the intensity of rainfall is more than the infiltration capacity of soil, then the infiltration rate will be
Answer: equal to infiltration capacity
24
Cyclonic precipitation is caused by lifting of an air mass due to
Answer: pressure difference
26
The most suitable material for the central impervious core of a zoned embankment type dam is
Answer: clay mixed with fine sand
27
As compared to gravity dams, earthen dams
Answer: require less skilled labour
28
For wave action in dams, the maximum height of freeboard is generally taken to be equal to
Answer: 1.50 hw
29
The maximum permissible eccentricity for no tension at the base of a gravity dam is
Answer: B/6
30
When the reservoir is full, the maximum compressive force in a gravity dam is produced
Answer: at the toe
32
Hydrodynamic pressure due to earthquake acts at a height of
Answer: 4H/371 above the base
33
Horizontal acceleration due to earthquake results in
Answer: both (a) and (b)
34
The uplift pressure on the face of a drainage gallery in a dam is taken as
Answer: two-third of hydrostatic pressure at toe plus one-third of hydrostatic pressure at heel
35
When the upstream face of a gravity dam is vertical, then the intensity of water pressure at the water surface and at the base respectively will be
Answer: OandwII
36
The total capacity of a reservoir is 25 million cubic metres and dead storage is 5 million cubic metres. If the average volume of sediment deposition is 0.10 million cubic metre per year, then the usefulness of the reservoir will start reducing after
Answer: 50 years
37
Trap efficiency of a reservoir is a function of
Answer: capacity/inflow ratio
38
For a flood control reservoir, the effective storage is equal to
Answer: useful storage + surcharge storage -valley storage
39
The water stored in the reservoir below the minimum pool level is called
Answer: dead storage
40
The useful storage is the volume of water stored in the reservoir between
Answer: minimum pool level and normal pool level
