781. To avoid scouring from end of structure, it is necessary to provide a ________________ at the exit point?

A. Vertical cutoff
B. Stone apron
C. Stone boom
D. Stone blocks

782. Now- a -days the hydraulic structures are designed. Keeping in view the flow net, this was given by __________________?

A. Blight
B. Khosla
C. Lane
D. Darcy

783. At the end of hydraulic structure, the upward force of sub-soil water just becomes equal to the submerged weight of soil grains Then exit gradient will be called______________?

A. Submerged exit gradient
B. Critical exit gradient
C. Balanced exit gradient
D. All are correct

784. Mostly the hydraulic structures founded on ____________ soils fails because of undermining and uplift pressure?

A. Stable
B. Rocky
C. Impermeable
D. Permeable

785. The depth before the jump is always less then the depth after the jump. The depth before the jump is called initial depth and depth after the jump is called_______________?

A. Afflux
B. Final depth
C. Sequent depth
D. Down stream water depth

786. The structures, which are constructed on the river bed upstream of head regulator. With this clear water enters in canal such structures are called______________________?

A. Silt excluders
B. Silt ejectors
C. Vortex pipes
D. Silt control structures

787. In high floods, to avoid spilling of flood water over the gates, a wall is provided from pond level to high Flood level. This wall spans for the entire length of regulator, rest on piers, sustain water pressure by its weight called_____________________?

A. Retaining wall
B. Divide wall
C. Breast wall
D. Cantilever wall

788. The water way from a weir is determined by using Lacey’s wetted perimeter i.e. P=_______(Q)1/2 ?

A. 3.50
B. 3.75
C. 4.75
D. 5.75

789. When a weir is constructed, the downstream .bed of the river goes on eroding and consequently causes progressive lowering of the bed on downstream of weir called__________________?

A. Retrogression
B. Lowering down of bed
C. Ponding on down stream
D. All are correct

790. For strong Hydraulic jump containing maximum energy, the down stream glacis should be sloped at a slope of ______________ to dissipate max: energy?

A. 2:1 to 2.5:1
B. 2.5:1 to 3:1
C. 3:1 to 5:1
D. 5:1 to 6