221. Which one of the following constitutes the basic assumption of unit-hydrograph theory? Time invariance and linear response
222. The following parameters relate to the design of weirs on permeable foundations:
1. exit gradient.
2. uplift pressure.
Design of the downstream end pile of the
weir depends upon
223. Given that the base period is 100 days and the duty of the canal is 1000 hectares per cumec, the depth of water will be 86.4 cm
224.A pumped storage plant is a peak load plant
225.If p is the precipitation, a is the area represented by a rain gauge, and n is the
number of rain gauges in a catchment area, then the weighted mean rainfall is
226.Depth-Area-Duration curves of precipitation are drawn as maximising envelopes through the appropriate data points
227.
A. Conservation reservoirs-Controlled outlets B. Retarding basins-Uncontrolled outlets C. Flood plains-Temporary storage of flood water D. Flood walls-Flood-fighting
228.The following four hydrological features have to be estimated or taken as inputs before one can compute the flood hydrograph at any catchment outlet
1. rainfall hydrograph
2. infiltration index
3. unit hydrograph
4. base flow
The correct order in which they have to be employed in the computations is
229.
Tailwater curve much above jump height curve-Sloping apron Tailwater curve slightly above jump height curve-Ski jump bucket Tailwater curve coinciding with jump height curve-Basin at bed level Tail water curve below the jump height curve-Sunk basin
230.The Standard Project Flood is derived from the probable maximum
precipitation in the region
231.
A.Canal drop-Control of bed grade B. Canal escape-Control of full supply level C. Canal cross regulator-Control of flow depth D. Canal outlets-Control of discharge
232.For medium silt whose average grain size is 0.16 mm, Lacey's silt factor is likely to be 0.70
233.
A. Minor irrigation work-Surplus weir B. Medium irrigation project in interior area-Syphon spillway C. Earth dam across main river-Saddle spillway D. Masonry dam on good rock-Ogee spillway
234. Mean precipitation over an area is best obtained from gauged amounts by
orographically weighted isohyetal method
235. The following steps are involved in arriving at a unit hydrograph
1. Separation of base flow
2. Estimating the surface runoff in volume
3. Estimating the surface runoff in depth
4. Dividing surface runoff ordinates by depth of runoff
236. Probability of a 10-year flood to occur at least once in the next 4 years is
35%
237. The following data were recorded from an irrigated field
1. Field capacity : 20%
2. Permanent wilting point: 10%
3. Permissible depletion of available soil
moisture : 50%
4. Dry unit weight of soil :1500kgf/m3
5. Effective rainfall: 25 mm
Based on these data, the net irrigation requirement per metre depth of soil will be
50 mm
238. Depth-area-duration curves would seem to resemble arcs of a circle concave upwards with duration increasing outward
239. The spacing of tile drains to relieve waterlogged land is directly proportional
to the coefficient of permeability of the soil to be drained
240. The maximum permissible suction lift for centrifugal pump in practice (at sea level and at 30°C) is 6 m
241. An aquifer confined at top and bottom by impermeable layers is stratified into three layers as follows:
The transmissivity (m /day) of the aquifer is
260
242. In a flow-mass curve study, the demand line drawn from a ridge does not intersect the mass curve again. This implies that
the demand cannot be met by the inflow as the reservoir will not refill
243. The following rainfall data refers to stations A and B which are equidistant
from station 4X
The value of P will be 200
244. Consider the following statements :
1. A 100-year flood discharge is greater than a 50-year flood discharge.
2. 90% dependable flow is greater than 50% dependable flow.
3. Evaporation from salt-water surface is less than that from fresh-water surface
245.If a 4-hour unit hydrograph of a certain basin has a peak ordinate of 80 m³/s, the peak ordinate of a 2-hour unit hydrograph for the same basin will be
greater than 80 m³/s
246.
A. Dalton-Evaporation B. Snyder-Synthetic unit hydrograph C. Blaney Criddle-Consumptive use equation D. Sherman-Unit hydrograph
247. A culvert is designed for a peak flow Qₚ on the basis of rational formula. If a storm of the same intensity as used in the design and twice the duration occurs, then the resulting peak discharge will be Qₚ
248
A. Specific yield-Volume of water drained by gravity per unit volume of aquifer B. Specific capacity-Well yield per unit drawdown C. Specific retention-Volume of water retained per unit volume of aquifer D. Specific storage-Volume of water released from unit volume of aquifer for unit decline in piezometric head