MCQ
621. In the estimate of design flood, Dickens assumes that high flood in cumecs, is proportional to catchment area raised to the power
1/4
1/2
3/4
2/3
622. The main function of a divide wall is to
Control the silt entry in the canal
Prevent river floods from entering the canal
Separate the under-sluices from weir proper
Provide smooth flow at sufficiently low velocity
623. The sensitivity of a rigid module is
Zero
Between zero and one
1
Infinity
624. For the upstream face of an earthen dam, the most adverse condition for stability of slope is
Sudden drawdown
Steady seepage
During construction
Sloughing of slope
625. Lining of irrigation channels
Increases the water-logging area
Decreases the water-logging area
Does not change the water logging ares
None of the above
626. The stage of river carrying a discharge of Q m/sec at a point is 10 m and slope of water surface is (1/4000). The discharge of a flood same point and same stage of 10 m with a water surface slope of (1/1000) will be
3/sec
0.5 Q m3/sec
2 Q m3/sec
4 Q m3 sec
627. Pick up the correct statement from the following:
Yield of a drainage basin is the run off at any time
Yield of a drainage basin is the run off over long periods
Yield of a drainage basin is expressed as surface run off per year
Run off is expressed as total volume per day
628. Vertical drop fall is satisfactory for a height upto
0.5 m
1.5 m
3.5 m
5.0 m
629. Seepage through embankments in an earthen dam is controlled by
Drainage filters
Relief wells
Drain trenches
Provision of downstream berms
630. When the reservoir is full, the maximum compressive force in a gravity dam is produced
At the toe
At the heel
Within the middle third of base
At centre of base
631. Izzard formula for the time of concentration in minutes for the plots having no channels, is (where Lo is the length of overland flow in metres and Kp rainfall intensity in cm/hour)
T= 111 b. L0 1/3/(Kp)2/3
Т= 222 bL10 1/2/(Kp)1/3
T= 333 b. LO/Kp
T= 111 b. LO 1/3/(Kp)2/5
632. Hydrograph is a graphical representation of
Surface run off
Ground water flow
Rain fall
Discharge flowing in the river
633. Precipitation caused due to striking of air masses with a topographical feature, is called
Orographic precipitation
Convective precipitation
Cyclonic precipitation
None of these
634. Discharge curve may be extended by logarithmic method if
Cross section of river is uniform
River is broader and shallower
River is of any type
None of these
635. Indian Meteorological department uses the standard gauges whose collectors have apertures of
50 or 100 sq. cm area
100 or 150 sq. cm area
100 or 200 sq. cm area
250 or 500 sq. cm area
636. An aggrading river is a
Silting river
Scouring river
Both silting and scouring river
Neither silting nor scouring river
637. The rainfall at any place is described by
Its intensity
Its duration
Its frequency
All the above
638. The major resisting force in a gravity dam is
Water pressure
Wave pressure
Self-weight of dam
Uplift pressure
639. Pick up the correct statement from the following:
If ground water enters the channel, the channel is known as effluent channel
If water goes out of channel to meet ground water, the channel is said to be influent stream
If the water table is at higher level than the water level in channel, ground water flows to the stream
All the above
640. The equation V (1000 ID10/60)×(1.8T+42) which is used for determining the velocity of ground water flow in metres per day is known as
Meinzer's formula
Slichter's formula
Darcy's formala
Hazen formula