681. Direct runoff is the sum of __________________?
A. Surface run-off and mass flow
B. Bass flow and ground water run off
C. Sub-surface run off and deep percolation
D. Surface run off and flow
682. Which of the following has highest-coefficient of discharge_____________________?
A. Sharp edged orifice
B. Venturi meter
C. Broad crested weir
D. Cippoletti weir
683. Aeration holes are provided to reduce the inside saturation pressure ____________________?
A. In a weir with end contractions
B. In a suppressed weir
C. In a cippoletti weir
D. In all weir
684. generally useful life of a reservoir is considered terminated when its -gross storage is reduced by _______________ of the design capacity of the reservoir?
C. 50% l
685. The centre of pressure of a plane submerged area which holds it in equilibrium is ____________________?
A. Always below the centre of gravity of the area
B. Coincident with centroid of area if its plane is vertical
C. Always above the centroid of the area
D. Independent of the inclination of area
686. the phenomenon of evaporation from water surfaces, from soil surfaces around the plants and from plants and transpiration from plants is called ___________________?
D. All are correct
687. The free distance on the paddy surface which a wind can travel to any point to rise waves is called_________________?
A. Wave wash
D. Wave amplitude
688. The line in a flow net which shows the direction of flow of water through a soil mass beneath dam are called _________________?
A. Equipotential lines
B. flow lines
C. Section lines
D. Streak lines
689. A mine or tunnel for collecting seepage water in rock or dam is called ____________________?
A. Water tunnel
B. Seepage gallery
C. Seepage tunnel
D. Seepage Drain
690. Mean velocity of flow in a river can be directly measured by means of ______________________?
A. Dickne’s formula
B. Current meter
C. Surface floats
D. Rod floats