81. The discharge passing over an ogee spillway is given by
where, L is effective length of spillway crest and H is the total head over the
spillway crest including velocity head.
82. Coefficient of discharge of an ogee spill way depends on depth of approach and upstream slope , depends on downstream apron interference and downstream submergence
83. Which of the following spillways is least suitable for an earthen dam ?
ogee spillway
84. In case of non-availability of space due to topography, the most suitable
spillway is shaft spillway
85. In a chute spillway, the flow is usually super critical
86 For the upstream face of an earthen dam, the most adverse condition for stability of slope is sudden drawdown
87. If there are two canals taking off from each flank of a river, then there will be
two divide walls and two undersluices
88. Generally the weir is aligned at right angles to the direction of the main river
current because it ensures less length of the weir , it gives better discharging capacity ,it is economical
89. The main function of a divide wall is to separate the undersluices from weir
proper
90. A divide wall is provided at right angle to the axis of weir
91. As compared to crest of the normal portion of the weir, the crest of the under
sluice portion of weir is kept at lower level
92. Silt excluders are constructed on the river bed upstream of head regulator
93. If h is the-'ordinate of hydraulic gradient line above the top of the floor and G is
specific gravity of floor material, then the thickness of floor is given by the formula
h/(G-1)
94. According to Khosla's theory, the exit gradient in the absence of a downstream cutoff is infinity
95. The minimum size of stone that will remain at rest in a channel of longitudinal
slope S and hydraulic mean depth R is given by 11 RS
96. The ratio of average values of shear stresses produced on the bed and the banks of a channel due to flowing water is greater than 1
97. If the critical shear stress of a channel is Τc, then the average value of shear stress required to move the grain on the bank is 0.75 Τc
98. A water shed canal avoids the cross drainage works
99.A canal which is aligned at right angles to the contour is called side slope canal
100.Garret's diagrams are based on Kennedy's theory