When the high flood level of a drain is safely below the canal bed so drainage water flows freely under gravity, this structure is called ___________________?
Show answer Hide answer
Answer: A. Aqueduct
Explanation
An aqueduct carries an irrigation canal safely above a natural drainage channel. This cross-drainage structure is used when the high flood level of the drain remains below canal bed. Gravity flow allows the canal water to pass unimpeded over the underlying natural stream. Cross-drainage works are essential engineering structures where canals and natural streams intersect. Aqueducts function like water bridges, supporting canal troughs over drainage valleys. Hydraulic design ensures the drain has sufficient waterway area beneath the aqueduct piers.
Canal route planning often requires aqueducts to cross rivers and streams without mixing waters. Proper sizing prevents floodwaters from backing up and damaging upstream agricultural lands. Civil engineers select aqueducts when favorable relative bed levels permit gravity drainage. Option B carries a canal under pressure beneath a drainage channel using siphonic action. Option C is a broad category encompassing all types of canal-stream crossing structures. Option D is an invalid technical term not used in standard hydraulic engineering.
- Subject
- Agriculture
- Category
- Agriculture
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Water application efficiency improves if the irrigated plot is __________________?
Show answer Hide answer
Answer: C. Rectangle
Water application efficiency improves when irrigated field plots are laid out in rectangular shapes. Rectangular plots facilitate uniform advance and recession of irrigation water across the field. This geometric layout...
Q2. When a reservoir is full on the upstream side, maximum stresses occur upon __________________?
Show answer Hide answer
Answer: B. Bottom of dam
When a dam reservoir is full, maximum compressive and overturning stresses concentrate at the base. Hydrostatic water pressure creates a large overturning moment resisted by the dam base. The downstream toe experiences m...
Q3. Root-zone water storage efficiency is dependent upon __________________?
Show answer Hide answer
Answer: A. Porosity
Root-zone water storage efficiency and capacity depend fundamentally on soil porosity. Porosity determines the total volume of pore space available to store capillary soil moisture. Soil pore size distribution dictates h...
Q4. Which of the following exhibits the highest coefficient of discharge _____________________?
Show answer Hide answer
Answer: B. Venturi meter
A Venturi meter operates on differential pressure principles and exhibits a very high discharge coefficient. Gradual convergence and divergence minimize flow separation losses inside the Venturi meter. High discharge coe...
Q5. When a reservoir is at full capacity, maximum compressive stress in a gravity dam occurs at ___________________?
Show answer Hide answer
Answer: A. At the toe
When a reservoir is full, the maximum compressive stress in a gravity dam occurs at the downstream toe. Water pressure creates an overturning moment shifting resultant forces toward the downstream face. High compressive...
Q6. The wilting point marks the threshold beyond which crops suffer stress and water becomes unavailable; this point is reached after _________________?
Show answer Hide answer
Answer: C. 20% water available
Crops experience severe wilting and moisture stress when available soil moisture falls to 20%. This permanent wilting point marks the critical threshold where plant roots can no longer extract water. Cell turgor pressure...