MCQ
641. the exit gradient in the absence of a downstream cut-off is
Unity
Infinity
Very large
642. In India the recording type rain gauge generally used, is-
Weighing type
Tipping type
Float recording type
None of these
643. 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
644. The quantity of water retained by the sub-soil against gravity, is known
Yield
Porosity
Specific yield
Specific retention
645. If the loss due to friction in pipes is 4 m, the total losses in strainer and bends may be taken as
0.10 m
0.20 m
0.5 m
1.0 m
646. The net speed under which the turbine reaches its peak efficiency is called
Design speed
Rated speed
Gross speed
Operating speed
647. 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
648. From the data of the rain storm shown in the below figure, the value of Windex is
1.5 cm/hour
2 cm/hour
2.5 cm/hour
3 cm/hour
649. 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
650. Pick up the correct statement from the following:
Absolute humidity at a given temperature is equal to weight of moisture present in a unit volume.
Relative humidity is the ratio of actual vapour pressure and saturation vapour pressure at the same temperature.
Relative humidity is the ratio of the weight of the vapours present per unit volume to the weight of vapours which could be contained at the same temperature when fully saturated.
All the above
651. Infiltration capacity of soil depends upon
Number of voids present in the soil
Shape and size of soil particles
Arrangement of soil particles
All the above
652. Which of the following can be used as a meter fall?
Vertical drop fall
Flumed glacis fall
Unflumed glacis fall
All of the above
653. 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
654. Water contains
One hydrogen atom and one oxygen atom
Two hydrogen atoms and one oxygen atom
One hydrogen atom and two oxygen atoms
Three hydrogen atoms
655. Which of the following spillways is least suitable for an earthen dam?
Ogee spillway
Chute spillway
Side channel spillway
Shaft spillway
656. 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)
657. Horizontal acceleration due to earthquake results in
Hydrodynamic pressure
Inertia force into the body of the dan
Both (A) and (B)
None of the above
658. 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
659. For wave action in dams, the maximum height of freeboard is generally taken to be equal to
0.5 hw
0.75 hw
1.25 hw
1.50 hw
660. 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