This set of Irrigation Engineering Problems focuses on “River Intakes”.
1. River intakes is usually situated on ____________________
a) the convex side of the curve
b) the concave side of the curve
c) straight reach
d) the downstream side of a sewer outfall
Explanation: The structure may vary from a simple concrete block supporting the end of the conduit pipe to huge concrete towers. It is constructed at the entrance of the conduit. The basic function is to help in safely withdrawing water from the reservoir over a predetermined range of pool levels.
2. Which of the following intake structure is widely used in small works?
b) Simple submerged intakes
c) Wet intake towers
d) Dry intake towers
Explanation: The main disadvantage of simple submerged intakes is that they are not easily accessible for repairing of their gates etc. But, these are economical and do not obstruct navigation and are widely used in small works. These are particularly suitable as water-supply intakes from small rivers.
3. A trash rack is not required at the entrance of a ____________________
a) siphon spillway
b) drum gate installation
c) morning glory spillway
d) high-head gate installation
Explanation: Drum gates can control the reservoir level upstream to precise levels automatically and without the assistance of mechanical power. It is completely enclosed on all three sides as well as on the ends forming a water-tight vessel and is hinged at the upstream end.
4. Bar screens used to cover dam outlets to prevent entry of debris or ice into the sluiceway conduits are called ______________
a) gate controlled ports
b) projecting collars
c) trash racks
Explanation: The trash rack is generally provided as a cover for the entrance to intakes and dam outlets so as to prevent the entry of debris, ice, etc into the conduit. These are bar screens made from steel bars spaced at 5 to 15 cm center to center in both directions.
5. Which of the following statement is incorrect?
a) Water can be withdrawn from any selected level of the reservoir using dry intake towers
b) Intake towers have to be designed for the worst combination of hydrostatic wind earthquake and wave forces
c) Dry intake towers are lighter in construction as compared to wet intake towers
d) In dry intake tower, the water is directly drawn into the withdrawal conduit through the gated entry ports
Explanation: The water through the entry ports with gates is directly drawn into the withdrawal conduit in a dry intake tower. Dry intake towers is heavier in construction as it is subjected to additional buoyant forces even if the gates are closed. There are separate gate controlled openings for the conduit in a wet intake tower and openings are also made into the shaft.
Sanfoundry Global Education & Learning Series – Irrigation Engineering.
To practice all areas of Irrigation Engineering Problems, here is complete set of 1000+ Multiple Choice Questions and Answers.