181. According to Indian standards, the number of raingauge stations for an area of 5200 km² in plains should be 10
182. For a storm of given duration, if the intensity of storm corresponding to a
return period of T is I, then the intensity of storm for same duration but corresponding to a return period of T₁ (where T₁ > T) will be greater than I
183. What is the probability of a flood equal to or greater than 25 years flood occurring twice in the next three years ? 72/15625
184. The rainfall in four successive 12 hours period on a catchment are 40, 80, 90 and 30 mm. If the infiltration index Φ for the storm is 5 mm/hour, then the total surface run off will be 50 mm
185. The 6-hour unit hydrograph of a catchment of area 180km2 ia triangular in
shape. If the peak ordinate of this hydrograph is 10 mVsec, then the time
base is 100 hours
186. Percentage of raingauge stations which should be equipped with self recording gauges for knowing the intensity of rainfall should be about 10%
187. If the same catchment area is situated in three zones X, Y, Z where X, Y and Z
represent flat regions of tropical zone, mountaneous region of tropical zone and
arid zone respectively, then the relation between the desirable number of
raingauge stations in these three zones Nx ,Ny and Nz respectively is
Ny > Nx > Nz
188. If the coefficient of variation of rainfall values at 4 raingauge stations is 30% and permissible error in the estimation of mean rainfall is 10%, then the additional number of raingauge stations required in the catchment is 5
189. Assertion A : Under identical conditions, the evaporation from sea water is less than that from fresh water.
Reason R : Vapour pressure of sea water is less than that of pure water
Both A and R are true and R is the correct explanation of A
190. In a siphon aqueduct the most severe condition of uplift on the floor occurs
when canal is dry and drain is at high flood level
191. The double mass analysis is adopted to check the consistency of data
192. Retrogression of downstream levels, generally considered in the design of
weirs or barrages, is higher at low water levels stage than at high flood stage
193. Cross-regulators in main canals are provided to head up water for adequate supply into the off-taking channel
194. For a barrage, the exit gradient is independent of the depth of upstream cutoff
195. For the upstream slope of an earth dam, the most critical condition is sudden draw down condition
196. Bligh's creep theory of seepage assumes equal weightage to horizontal and
vertical creeps
197. The sequent peak algorithm is a method used in the estimation of the
minimum reservoir capacity needed to meet a given demand
198. The probable maximum flood is an extremely large but physically
possible flood in the region
199. The probable maximum precipitation at a station is the greatest rainfall for a given duration that is physically possible
200. The flow duration curve is a plot of the stream discharge against the
percentage of time the flow is equalled or exceeded