MCQ
761.
Seepage through embankments in an earthen dam is controlled by
Drainage filters
Relief wells
Drain trenches
Provision of downstream berms
762.
For the estimate of high floods in fan-shaped catchment, the formula used is
Dicken's formula
Ryve's formula
Inglis formula
None of these
763.
To determine the discharge at a section in a stream from its rating curve, the required data are (1) Slope of water surface at the section (ii) Stage at the section (ii) Current meter readings at the section The correct answer is
(i) and (ii)
(ii) and (ii)
Only (ii)
Only (iii)
764.
The sensitivity of a rigid module is
Zero
Between zero and one
1
Infinity
765.
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
766.
The critical depth in a channel can be produced
By raising the bottom of the channel
By lowering the bottom of the channel
By decreasing the width of the channel
Both (a) and (c) of above
767.
The peak of a 4 hour flood hydrograph is 240 m3 /sec. If the rainfall excess is 80 mm and base flow which is constant is 40 m3/sec, peak of 4hours unit hydrograph will be
20 m3/sec
25 m3/sec
30 m3/sec
35 m3/sec
768.
The major resisting force in a gravity dam is
Water pressure
Wave pressure
Self-weight of dam
Uplift pressure
769.
The run off a drainage basin is
Initial recharge + ground water accretion + precipitation
Precipitation ground water accretion + initial recharge
Precipitation ground water accretion + initial recharge
Precipitation ground water accretion – initial recharge
770.
Hydrograph is a graphical representation of
Surface run off
Ground water flow
Rain fall
Discharge flowing in the river
771.
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
772.
An aggrading river is a
Silting river
Scouring river
Both silting and scouring river
Neither silting nor scouring river
773.
The rainfall at any place is described by
Its intensity
Its duration
Its frequency
All the above
774.
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
775.
Which of the following can be used as a meter fall?
Vertical drop fall
Flumed glacis fall
Unflumed glacis fall
All of the above
776.
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
777.
The quantity of water retained by the sub-soil against gravity, is known
Yield
Porosity
Specific yield
Specific retention
778.
The net speed under which the turbine reaches its peak efficiency is called
Design speed
Rated speed
Gross speed
Operating speed
779.
The main cause of meandering is
Presence of an excessive bed slope in the river
Degradation
The extra turbulence generated by the excess of river sediment during floods
None of the above
780.
In the derivation of Thiem's formula, Q = (S1- S2)/[2.3 log10(/) the following assumption is not applicable
The aquifer is homogeneous and isotropic
Flow lines are radial and horizontal
The slope of the water surface is too small
The well has been sunk up to the surface of the unconfined aquifer